This is revealed in the minutes - leaked to Newsnight (download them here (pdf)) - of a meeting of senior national officials - the party's deputy chairmen and vice chairmen - held on 28 October last year.

The minutes say:

"Care needs to be taken over the candidates that have the potential to embarrass the Party - there will now be a fortnightly meeting to assess the watch-list of candidates, and the reasons they are on the list needs to be taken into consideration."

And the document shows that a Conservative Central Office official has even been appointed to keep a close eye on what these potential trouble-makers get up to:

"The public output e.g. blogs, websites, press releases of candidates will [sic] now to be monitored by a new member of the CRD team," the minutes read. "Let JM or Stephen Gilbert know if there are any problems with candidates - de-selection should be the last option." [JM is probably John Maples MP, the Deputy Chairman in charge of candidates.]

The minutes make it clear, however, that Central Office thinks that local associations are often a bigger problem than individual candidates.
"But there is nothing to deal with the awkward associations - senior volunteers to help?"

And the party is taking measures to keep their potential candidates on message, even before they have been elected, according to the leaked report - by arranging for candidates to meet the Chief Whip at Westminster, Patrick McLoughlin:

"The Chief [Whip] is keen to meet with the candidates so they can get used to being line-managed by the Whips' Office."

Line managed? An interesting phrase.

The minutes show that despite David Cameron's slogan of 'Power to the People' - reiterated in spirit in his economy speech this week - when it comes to his own party organisation he is more centralist than ever, and that Central Office doesn't fully trust its candidates or local associations. In monitoring candidates and their output so closely, the Conservatives have clearly adopted many of the techniques honed by Peter Mandelson and Tony Blair for New Labour in the 1990s. These were designed to ensure that the new Labour MPs elected in 1997 were less troublesome than many of their predecessors.

What will also concern many candidates and grassroots activists is the suggestion in the minutes that extra resources may have to be pumped into constituencies which have candidates who are female or come from ethnic minorities. This seems designed to save the party from the potential that such seats might be lost in disproportionate numbers.
"Of 250 candidates, 70 are women and 10 are of an ethnic minorities [sic] - something extra needs to be done to ensure that these ones are not lost."

In response to a questions from Newsnight, a Conservative Party spokesman refused to identify the candidates with "the potential to embarrass the party".

But he said: "It is quite standard for political parties to monitor their candidates - it would be extraordinary if they did not."

This is how the Cabinet Office, in its official complaint to the Metropolitan Police, described the series of leaks from the Home Office, which ultimately led to the arrest of Damian Green MP. The letter, released to the Public Administration Select Committee, is dated incorrectly September 8th, it was in fact sent on October 8th.

The letter says the Government was in no doubt, but a lot doubt appears to exist now.

It begs the question whether the Government oversold this complaint to the police, which might explain their seemingly heavy-handed response. As of now there is no evidence that anything affecting National Security was involved.

In fact, had any national security related material been involved it would have been far easier for the police to make arrests under the Official Secrets Act rather than the common law offence they used.

Watch the Head of the Civil Service, Sir Gus O'Donnell gracefully avoid this issue in the video below from the Committee evidence session this morning.

Having spotted Mr Abrahams in the distance at another party on Monday night I was curious as to what had happened to the police investigation into his case - and indeed a similar story which dominated politics at the start of this year - the Peter Hain funding affair. Police passed the two cases to the Crown Prosecution Service last June and July respectively, but since then we've heard not a cheep from the CPS. Had the cases been quietly dropped? I wondered.

No. The two cases are "still under review", a CPS spokesman told me this morning, but he couldn't give me any guidance as to when the CPS might come to a decision on whether to prosecute.

Mr Abrahams seemed strategically placed in the centre of the room last night, where people would hardly fail to spot him. And he seemed in a pretty good mood last night, and it wasn't just the excellent Guinness and food provided by our Irish hosts. He claims that the police told his solicitor last March that he was "exonerated". And indeed when I rang his solicitor Louis Charalambous, this morning, he confirmed to me: "He will not face prosecution".

But that, of course, still leaves Peter Watt in the frame. He's the Labour Party General Secretary who approved the Abrahams donations, should have known what the law was, and who resigned over the affair.

It would be a wonderful watch.

He met us in his home town of Winstead, which still looks like an old-style American town, with a main street full of good old-fashioned private shops, and not wrecked by a soulless shopping mall. We caught up with him at the local high school, and then he took us into the local fix-it shop, the health food store, and his barber's, where even a famous presidential candidate has to wait in line to get his hair cut. Nader's aides told us that it was the first time he had ever allowed a TV team to film him on his home patch.

Ralph Nader, who is now 74, is known to many people these days as they man who ruined things for Al Gore (and won it for George W Bush) by standing in 2000, when he gained almost three million votes, and 2.74% of the national vote. In Florida, he won more than 97,000 votes, many times Al Gore's losing margin of 537. Nader insists this argument is "rubbish", and claims that his candidature in 2000 actually helped Gore, by pushing him to take up more popular, radical positions.

Nader is quick to point out that Time magazine has twice included him in their list of the 100 most influential Americans of the 20th century, not for his role in 2000, of course, but his work as a citizens' rights advocate, pushing through laws in the 1960s and 1970s on consumer issues, environmental protection and workers' rights. In 2006 a panel of historians recruited by Atlantic Monthly ranked Nader at number 96 in their 100 most influential Americans in history, just one ahead of Richard Nixon. Neither of the president Bushes, nor Clinton, made it into the historians' top hundred.

(Incidentally, the 1952 Democrat nomination was also contested by Jeffrey Archer's half-brother-in-law, the Connecticut senator Brien McMahon, but that's another, quite fascinating, story.)

The real answer is 1928 - 80 years ago - when neither the sitting President, Calvin Coolidge, nor his Vice President Charles Dawes, contested any part of the election.

For record, President Hoover was beaten in 1932, President Roosevelt won in 1936, 1940 and 1944, and Truman won in 1948.

After 1952, President Eisenhower fought in 1956; Vice President Nixon in 1960; President Johnson in 1964; Vice President Humphrey in 1968; President Nixon in 1972; President Ford in 1976; President Carter in 1980; President Reagan in 1984; Vice President Bush in 1988; President Bush in 1992; President Clinton in 1996; Vice President Gore in 2000 and President George W Bush in 2004.

Before that election most polls gave Bradley a substantial lead, but then he lost. In short, the effect was identified as a distortion in opinion polls caused by voters who didn't want to vote for a black candidate, but didn't want to admit that to pollsters.

A similar effect was cited by some analysts - rightly or wrongly - when Hillary Clinton confounded expectations, and the polls, and beat Obama back in the New Hampshire Democrat primary earlier this year.

But my former Newsnight colleague Peter Kellner, now president of the polling company Yougov, has written an article for the Fabian Society suggesting that the Bradley Effect may be a bit of a myth these days. Indeed, he argues that current US polls may in fact UNDERSTATE Obama's lead, simply because, on the basis of past voting behavior, they may underestimate how many black voters will turn out. But with Barack Obama in the running this time, the argument goes, black people may be a lot more inclined to cast their ballots than ever before.

Intriguing stuff.

It's the first year since 1976 that neither a Bush nor a Clinton has been on either of the main tickets (though Hillary almost got there).

And remarkably 2008 has been the first presidential race since goodness-knows-when which has not been contested by either the sitting President, nor the incumbent Vice President.

But what year exactly was "goodness-knows-when"?

Think hard.

It's a surprisingly long time ago, and the answer's not as simple as you might think. I certainly got it wrong when an anorak friend posed the question a few weeks ago.

The full Government list has been published today, and while most attention is understandably elsewhere a few ideas have struck me.

The first is that while at cabinet level so-called 'Blairites' have been well-treated, lower down the ladder there seems to be an emphasis on loyalty.

Specifically from the 2001 generation of MPs three MPs who in September 2006 helped force Tony Blair to announce his leaving date have been promoted (Sion Simon, Kevan Jones and Chris Bryant) while two who were loyal to Blair in that crisis have been sacked (Meg Munn, although she was already in Government, and Tom Harris who signed a letter loyal to Blair). Meg Munn I understand received the call while she was on a work trip to Mexico.

Indeed Tom Harris was promoted to Government initially by Tony Blair to replace Tom Watson who had just resigned. The message to ambitious MPs is not hard to spot.

The second is that Ian Austin's departure as the Prime Minister's PPS and replacement by Jon Trickett is more significant than has been generally commented.

It is a calculated attempt to reach out to the left of the party (which has been partly stymied by Jon Cruddas's refusal to take a job on the terms offered), and Ian Austin was very influential in Downing Street's media operation: he was Damian McBride's predecessor as Brown's spinner.

The third is that the departure of Tony McNulty as Home Office Minister is significant both for the 42-days policy which he did so much to take though the Commons, but also for his new role as Employment Minister - this is clearly an issue that the Government thinks it will need a feisty Commons and media performer in the next few months.

But surely, before the recent reforms to the Lords, I suggested, he wouldn't have needed a new title. HRH the Prince of Darkness would have been there by right.

Peter Mandelson was due to step down as a European Commissioner next year, and had already started thinking of a new career in business. But the chance to return once more to cabinet was irresistible. In part, it brings what one friend calls "closure" to the huge sense of personal injustice he harboured over his second forced resignation - over the Hinduja passport affair - a resignation which most people in politics now accept was unfair.

Peter Mandelson returns to cabinet in much changed circumstances compared with his two brief spells in the early Blair years. He has established a new, independent reputation in Europe, where he is generally thought to have done well in the job of trade commissioner. Whereas in the past, his position stemmed simply, in the eyes of many people, from his closeness to Tony Blair. Indeed that was why so many in the media pursued him so relentlessly, helped to a large degree, of course, by key figures in the Brown camp. Presumably the latter will no longer be a problem.

It suggests a new attitude to government by Gordon Brown - a willingness to have colleagues around the cabinet table who will stand up to the PM when necessary. Among the previous team it was hard to see anyone who would do that. A return, perhaps, to the style of Attlee, Wilson and Callaghan, who happy to have fellow big beasts in cabinet who might easily disagree.

Which brings me to the strange story of Jon Cruddas, the left-wing MP who did so well in last year's deputy leadership contest. The word was that Cruddas would now be brought into government, perhaps as housing minister. But that job has now gone to Margaret Beckett. There's a strange silence from the Cruddas camp today, so something may yet happen, especially since not all the ministerial posts have yet been filled.

Beckett's return to ministerial office seems a pretty selfless act, for she's got a post which isn't even in cabinet (though she can attend cabinet meetings). And yet only 15 months ago she held the mighty post of Foreign Secretary. And previously she's been deputy leader of her party, and indeed was briefly, in 1994, Labour's acting leader.

Finally, a small amusing footnote. The posts of Scotland (Jim Murphy) and Wales (Paul Murphy) are now held by men with the same name, a name which is Irish.

1. Winston Churchill (1940-55)
2. Margaret Thatcher (1975-90)
3. Harold Macmillan (1957-63)
4. David Cameron (2005 to date)
5. Edward Heath (1965-75)
6. John Major (1990-97)
7. William Hague (1997-2001)
8. Alec Douglas-Home (1963-65)
9. Michael Howard (2003-05)
10 Anthony Eden (1955-57)
11. Iain Duncan Smith (2001-03)

In our poll of activists, the positions of Winston Churchill and Margaret Thatcher were reversed.

1. Margaret Thatcher (1975-90)
2. Winston Churchill (1940-55)
3. David Cameron (2005 to date)
4. William Hague (1997-2001)
5. Harold Macmillan (1957-63)
6. John Major (1990-97)
7 Michael Howard (2003-05)
8. Alec Douglas-Home (1963-65)
9. Anthony Eden (1955-57)
10. Iain Duncan Smith (2001-03)
11. Edward Heath (1965-75)

And there's a long history of voters punishing parties when MPs resign from the Commons to take better-paid jobs elsewhere. Labour should remember what happened when Bruce Millan resigned to become a European Commissioner back in 1988, and Labour lost his Glasgow Govan seat, in a famous triumph for the SNP.

1. Clement Attlee, 1935-55
2. Tony Blair, 1994-2007
3. Harold Wilson, 1963-76
4. Hugh Gaitskell, 1955-63
5. Neil Kinnock, 1983-92
6. John Smith, 1992-94
7. Jim Callaghan, 1976-80
8. Gordon Brown, 2007-08
9. Michael Foot, 1980-83

So bad news for Gordon Brown, in eighth place, and a surprising showing for Hugh Gaitskell, who never served as PM or even won an election.

In our poll of well over 100 activists, Attlee again came top, and Foot was again bottom, but Gordon Brown did a lot better.

These rankings were:

1. Clement Attlee, 1935-55
2. Tony Blair, 1994-2007
3. Gordon Brown, 2007-08
4. Harold Wilson, 1963-76
5. John Smith, 1992-94
6. Neil Kinnock, 1983-92
7. Hugh Gaitskell, 1955-63
8. Jim Callaghan, 1976-80
9. Michael Foot, 1980-83

These occasions are strictly women-only, I'm told, which meant that not even Jacqui Smith's two male detectives were allowed into the room, and so had to sit patiently outside whilst the seven Guardian women and their 15 Labour Party guests wined, dined and talked.

At one point Polly Toynbee raised her favourite topic, asking whether Labour should increase taxes for richer people, as she argues passionately.

Jacqui Smith said she thought this was a terrible idea, a great betrayal of everything Labour had promised and stood for since 1997.

She was backed by Ruth Kelly, and I'm told, Tessa Jowell, who warned that if the rich had to pay more tax they would all flee to New York.

Several backbenchers made the case for higher tax, and interestingly they were joined by at least two rising stars form the junior ministerial ranks - the Solicitor General Vera Baird, and Harriet Harman's deputy Helen Goodman.

They both said Labour should pay a lot more attention to its grassroots supporters.

It all got very animated, exposing huge divisions within the government, on what's a big issue at the moment.

Eventually, having led the anti-tax forces at length, Jacqui Smith got up and announced she had to go.

Then, as she was walking out of the room, she turned and pointedly said to Vera Baird, "I hope you don't think I'm leaving because I'm in a strop, because I'm not!"

Update

Another source has since told me she reckons that Jacqui Smith walked out in anger at what her ministerial colleagues were saying.