Update: Since the publication of this article Philip Davies MP has asked it be made clear his decision to vote against the boundary review was based on long held opposition to the legislation and was not in the interests of self preservation.
Furious Tory MPs will attempt use a Commons vote on Tuesday to overturn a Lib-Lab alliance that could cost David Cameron the next election.
The changes, which will see the number of MPs cut from 650 to 600 and the boundaries moved, are thought to benefit the Tories to the tune of around 20 extra seats.
Nick Clegg initially supported the plan. But after Tory MPs killed off proposals to reform the House of Lords he instructed his MPs and ministers to vote against it.
The squabble is potentially one of the most serious coalition splits since 2010, as many on both sides see it as pure political tactics rather than an argument over policy.
David Cameron’s struggle to win a majority in 2015 is made even harder if the boundary review does not happen before the next election. He is hoping he can overturn the Lords vote today.
However it is a near impossible task, as the 57 Lib Dem MPs combined with the 255 Labour MPs total 312, enough to defeat the 303 Tories.
The prime minister is relying on support from the minor parties to swing the vote in his favour. If the six SNP MPs and eight DUP MPs vote with him he can win.
However he also faces the problem that not all Tory MPs can be relied to vote on party lines as the cut in the number of seats could see many out of a job.
Shipley MP Philip Davies has confirmed he plans to vote with Labour and the Lib Dems. Davies, who is no fan of the coalition, told HuffPost UK that while Clegg’s decision to oppose the changes helped him personally, he was less than impressed.
“How he has behaved is abysmal, It’s like a primary school child. It suits me on this issue but I don’t endorse his tactics,” he said.
The SNP has denied it has done a “deal” with the Tories on to vote with them. However on Monday afternoon a spokesperson for Alex Salmond’s party refused to confirm which way its MPs would vote.
But other minor parties look sure to vote against the Tories including Brighton’s Green Party MP Caroline Lucas.
“I will vote against the proposed boundary changes today because I think that constituency boundaries should reflect the communities that MPs represent, rather than just points on a map drawn in Whitehall," she said.
"These proposed changes would divide up the heart of Brighton and Hove in an absurd way that simply doesn’t reflect our distinctive communities and neighbourhoods. The Greens are also concerned that the attempt to reduce the number of seats, thereby increasing the ratio of constituents to MPs, would lead to weaker democratic representation for voters.”
Conservative MPs are furious at Clegg for sabotaging the boundary review. They believe it was the agreed price for allowing the Lib Dems to hold a referendum on changing the electoral system and that Lords reform was not part of any deal.
On Monday Tory MP Sarah Wollaston accused the Lib Dems of “betraying” the coalition.
“If the Lib Dems abandon the coalition agreement on boundary reform they will be seen to be abandoning fairness for narrow-self interest,” she said.
The Conservatives argue the current arrangement is unfair, as the party has to win a great share of the national vote in order to win the same number of MPs as Labour.Suggest a correction