Sainte-Laguë, cousin of d'Hondt

Wales' political anoraks have had a happy morning courtesy of the Welsh Secretary. To add to the d'Hondt method for the election of the Assembly's regional members, they have another - the Sainte-Laguë formula.

Sainte-Laguë? Saints alive, I hear you say. What is Sainte-Laguë? Put (relatively) simply, it's a close cousin of d'Hondt, that is to say a means of distributing party list seats proportional to votes cast.

Why has it reared its head today? That's where the anoraks stop and the hard politics start.

In her Green Paper this morning, the Welsh Secretary has signalled that it's highly unlikely that the next Assembly election in 2016 will be fought on the same constituency boundaries as the last one in 2011.

If - and it's still a big if - the Westminster boundary changes being planned by the UK Government become law, which would reduce the number of Welsh MPs to 30, I think it's an odds on bet that they will also legislate at the same time to change the Assembly 60 member voting structure from 40-20 to the same 30 constituency seats as Parliament with 30 more across five regional lists.

The reason that it's still an if is that it's still far from a done deal - some informed sources in Westminster put the chances of it actually becoming a reality at no more than 50-50. Although talk of it being used as a bargaining chip by David Cameron in return for Nick Clegg dropping the equally hot potato of Lords reform is - apparently - wide of the mark, it's exercising enough Tory backbenchers to make that 50-50 assessment fairly plausible.

If the reduction in the number of MPs should fall under the Westminster bus, I think it's clear that a unilateral move to 30-30 for the Assembly is highly unlikely. But the Welsh Secretary isn't going to leave things just as they are by the looks of it. It's likely that she will legislate to instruct the Electoral Commission to draw up new boundaries for the 40 constituency seats that will provide for a much fairer distribution of votes.

This morning's example was the disparity in electorate between Cardiff South and Penarth (76,715 electors) and Arfon (40,667 electors). As we've seen in the Westminster boundary proposals, small changes in where borders are drawn can result in big changes in voting terms, turning safe seats into marginals and vice versa.

The effect of those changes on the likelihood of one party winning an overall majority in the Assembly in future may be relatively mild, depending on how the boundaries are drawn. The effect of a more radical change to 30-30 constituency and list would be much more profound.

Cheryl Gillan called the solution "elegant and simple" in her briefing this morning, and while stressing that she did not have a firm preference in relation to any of the proposed changes, led the assembled hacks to understand that it was, at least, her "gentle preference".

Not so the Labour Party's position of 30 dual member constituencies, both elected by first past the post system. There was an outright rejection of this, with the clear message that any changes which would result in a lessening of proportionality from the Assembly's current system is firmly off the table.

So where does our new friend Sainte-Laguë come in?

Under the 30-30 proposals, the UK Government would couple the boundaries of Assembly constituencies with those of the new Parliamentary ones. But - as we've seen - from time to time, boundaries are redrawn at a Parliamentary level, which, again as we've seen, can lead to variations in the number of seats allocated to Wales. So it's possible that in a few years time, demographic changes or revised formulas could see the number of constituencies in Wales fall to, say, 29. But the Assembly, by law, must always have 60 seats over. Sainte-Lague is the mechanism for working out how the extra regional list seat would be allocated.

It's unlikely the Welsh Government are dwelling too long on the intricacies of Sainte-Laguë - but we're still waiting for their response to the Green Paper. Cheryl Gillan briefed Carwyn Jones on the proposals this morning. She'll have the chance to hear from all 60 AMs on Wednesday when she makes a statement to the Assembly on the Queen's Speech.


First Minister Carwyn Jones said: "There is no mandate for this. The electoral system for the Assembly is a matter for the people of Wales and no one else. "The Prime Minister has assured me that there would be no change to future electoral arrangements without the agreement of the Assembly."