Coalition deal on election boundaries under threat

Senior Liberal Democrats are willing to tear up the keynote Coalition deal on new election boundaries - providing Conservatives join the revolt, the Evening Standard can reveal.

The move would enrage David Cameron who is banking on a new map of parliamentary constituencies to boost the Conservatives' share of Commons seats at the next election.

A senior Lib-Dem source said some of Nick Clegg's MPs were willing to back out of the shake-up but they would need to be sure that Tory rebels would also defy Mr Cameron.

"It would be the worst of all worlds if a group of Liberal Democrats on their own voted against the reforms," said the source. "It is not something that could be done without members of other parties, including the Conservatives."

The issue is highly charged because Lib-Dem support for the new boundaries was explicitly promised in return for the Conservatives agreeing to a referendum on voting reform. The referendum was held in May but the Yes campaign, led by the Lib-Dems, was defeated by two to one.

A source close to the Prime Minister made clear that he expected his Coalition partners to honour their side of the deal. "They had their referendum on the alternative vote, now they have got to keep their promise on the boundaries."

A draft new map of parliamentary seats was published last week by the Boundary Commission and caused immediate consternation among MPs in all parties.

Experts think Labour could lose 20 to 30 seats but that the Liberal Democrats, who have only 57 seats at present, would be proportionally harder hit.

The shake-up aims to slash the number of MPs from 650 to 600 and alters the shape of many seats. Labour vowed to halt the reforms, which they say amount to "gerrymandering". The Tories insist the new map is fairer because seats will be roughly the same size for the first time.