EU Budget - when is a cut not a cut

David Cameron with Angela Merkel and European Parliament president Martin Schulz Image copyright Reuters
Image caption The UK's payments to the EU may rise even if total spending by Brussels falls

A cut in the European Union's budget.

That is what Parliament voted for last year when Tory eurosceptics united with Labour to defeat the government. That is what David Cameron's advisers believe he may soon be able to say he's achieved.

Although no deal has yet been done the numbers currently being discussed for the next seven year EU budget are more than 30 billion euros (£25.5bn) lower than the one it will replace.

It has been a long and dull night for the prime minister.

He and the 26 other EU leaders left the Brussels negotiating table at around 12.30 in the morning and were only called back about six hours later. .

Besides a brief meeting with Germany's Chancellor Merkel and France's President Hollande there was not a great deal - beyond I'm told a supply of espressos, haribos, and fruit - to fill the small hours as Brussels negotiators put pressure on other countries to accept a squeeze.

As in any negotiation nothing is agreed until everything is agreed and the signs are that there is still a way to go before Europe's leaders sign on the dotted line.

Even if a deal is done with a headline cut to the EU budget there will be much to scrutinise.

Will the cut be as big as the one Britain aimed for?

The benchmark Downing Street seem keen to use is the so-called EU payments ceiling - what David Cameron likes to call Europe's credit card. It was €942.8bn (£803.9bn) for the seven years from 2007-2013. The expectation is that the new ceiling may end up being around €908bn (£774bn).

His critics may point out that he has not achieved a freeze in line with the figure of €886 billion the Treasury has previously used.

This number was produced by taking the EU's spending in 2011 - as it happens a relatively low spending year - and multiplying it by seven to cover the period of the EU's budget. It was always an arbitrary figure but it is one that ministers used.

How much spending has Brussels managed to classify as "off budget"?

Some EU spending is and always has been classified in this way - for instance Europe's solidarity fund which gives member states help in the event of floods, forest fires and the like.

British officials insist that no existing spending will be reclassified but will the figures for this and other off budget funds grow?

How much will Britain's contributions to the EU increase?

David Cameron has always insisted that Britain's EU rebate was non negotiable. Nevertheless the value of it has been falling thanks to the last budget deal done by Tony Blair.

The result is that in the looking glass world of EU budgets the EU's total spending may fall whilst Britain's payments actually increase.