Nick Clegg took his revenge on David Cameron today by successfully killing Tory hopes of redrawing the electoral map in a way that would aid the prime minister's reelection, prompting a serious rift between the coalition parties.
Lib Dem and Labour MPs cheered as they narrowly defeated by 334 votes to 292 an attempt by the Conservative Party to change the number and size of constituencies before 2015.
In an unprecedented move reflecting the split between coalition parties on the issue, Cameron agreed to suspend the requirement for government ministers to exercise collective responsibility for the vote.
To successfully win the vote, the prime minister needed to convince the six SNP MPs and the eight DUP MPs to join him – however he failed to get them on side.
Earlier this month Clegg ordered his peers to vote against their coalition colleagues in the House of Lords and side with Labour in order to successfully delay the planned boundary review until after 2015.
The changes would have seen see the number of MPs cut from 650 to 600. It is thought the new constituency borders would have helped Cameron win a crucial extra 20 seats.
The Conservative Party argues the current arrangement is unfair, as the party has to win a greater share of the national vote in order to win the same number of MPs as Labour.
The 2015 general election will now be conducted on the same constituency boundaries as the 2010 election that produced the current coalition.
Clegg initially supported the boundary review. But after Tory MPs killed off proposals to reform the House of Lords he took revenge by instructing his MPs and ministers to vote against it.
Tory MPs are furious at the deputy prime minister's "betrayal", arguing the Lib Dems were granted a referendum on changing the electoral system in exchange for supporting the boundary review.
Portsmouth North MP Penny Mordaunt told the Commons "there was never any obligation for Conservatives to support Lords reform" as she attacked the "spite, pettiness and self-interest".
She said the Lib Dems had "exchanged their legendary sandals for flip-flops to keep their options open" for a coalition with Labour after 2015.
The Conservative leader of the Commons, Andrew Lansley, told MPs the Lib Dem alliance with Labour in the Lords was an "abuse of the parliamentary process".
He said for unelected peers to try and "manipulate" the basis on which the Commons was elected was a "democratic travesty".
According to the Labour Party four Tory MPs, David Davis, Philip Davies, Richard Shepherd and John Baron, voted with the Lib-Lab alliance.
Before the vote Philip Davies told HuffPost UK that while he was unimpressed with Clegg's behaviour, he did not want to see his constituency be erased by the boundary review.
“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.