The biggest Commons obstacle to the new boundaries could be Conservative MPs themselves

By Paul Goodman
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Reports suggest that Downing Street may seek to push the proposed boundary reforms through the Commons in alliance with Democratic Unionist MPs, Plaid Cyrmu MPs and even the SNP.

Let's leave aside for a moment the obstacles to the boundary changes winning the assent of the Lords (though the Commons can presumably have the final say if if it is determined to).

Let's also leave aside the problem of whether Conservative offers to the nationalist parties - such as a new Government of Wales Act - would win the support of the Liberal Democrats.

Instead, let's put the Commons numbers under a magnifying glass, and begin by assuming, sadly, that Labour will win the coming Corby by-election and keep the other seats it won in 2010.

First, add Ed Miliband's MPs, plus Corby, to the Liberal Democrats, the SDLP, the single Alliance MP, the Green, Sylvia Hermon and George Galloway. Then take away two Deputy Speakers.

I make that 320 MPs.

Then add the Conservatives to Plaid, the Scot Nats and the DUP, and then take the two Deputy Speakers away.

I make that 321 MPs.

I am not counting the five Sinn Fein MPs or the Speaker.  One might of course challenge these assumptions - the SDLP, say, could somehow be induced to vote with the Tories. Who knows?

And then there is the question of who would turn up on the night.  But the main problem for the Conservative whips, I think, is the Tory MPs who lose out from the boundary changes.

It is impossible at this stage to cite a definitive figure, but one account has put the Conservative loss UK-wide at about 15 seats.

I think it's unlikely that all will vote for their own demise - whatever the Whips promise. The biggest obstacle to the boundaries going through could turn out to be Tory MPs themselves.