Boundary changes at Westminster instigated by David Cameron have been met with dismay by many Tory backbenchers, who either face losing their seats or finding their newly-drawn constituencies will be extremely marginal. The Conservative manifesto policy to reduce the number of MPs by 50 has produced quite unexpected results for the Tories, who appear to have come-off much worse from proposals by the Boundary Commission than they'd expected.

Last night in Westminster Tory MPs were poring over plans to redraw the political map of Britain, in many cases discovering they would have to fight the next election with completely different seats. Some of the proposed changes by the Boundary Commission for England were greeted with disbelief as strangely-shaped constituencies emerged. According to some MPs, these new seats bear little or no reflection on the communities they attempt to enclose.

As reports emerged last night of some Tories ignoring the government whip on its flagship policy of police commissioners in a gesture of disgruntlement, what seemed to be a fairly benign coalition policy is now starting to look like a potentially long-running source of backbench resentment.

George Osborne faces a possible fight for political survival with another Tory MP in the northwest of England, after the Boundary Commission for England called for his seat of Tatton to be abolished. Yet the Chancellor is far from the only senior MP facing the loss of his current constituency.

As part of a highly confusing picture which will see a protracted game of musical chairs across the country in the coming years, George Osborne can expect to find 60 percent of his current seat moved into a new constituency. The likely scalp for the Tories in the northwest of England is Graham Evans, who finds much of his constituency of Weaver Vale carved up into other people’s seats.

Conservative associations in neighbouring seats could come under pressure from the party leadership to change their MP, although there’s no obvious Tory in the region who could reasonably be expected to take a peerage and stand aside. Most of the Tory MPs in Cheshire were elected in 2010, with the exception of Edward Timpson who won a by-election in the last Parliament.

In what will be cold comfort for Osborne, his Labour party counterpart Ed Balls is also facing months of uncertainty over his own seat, which is facing substantial alterations to accommodate the reduction in MPs. The Shadow Chancellor can expect to have to fight his Labour colleague Hillary Benn for the proposed new seat of Leeds South West and Morley.

The details of the changes to Britain’s electoral map were released to MPs and journalists at mid-day on Monday, but within hours news of the upheaval had seeped out onto Twitter and Facebook. The Boundary Commission for England published a large amount of documentation on its website, which will likely be chewed over by Westminster pundits for several days.

Much of the reaction on Twitter focused on the Tory MP Nadine Dorries, whose Bedfordshire seat appears to have been carved up in several directions.

Nick Clegg’s seat of Sheffield Hallam has been abolished, with the most likely replacement for the Deputy Prime Minister being a strangely-shaped new seat which takes in parts of southwest Sheffield, parts of the Peak District and Barnsley.

Embattled Energy Secretary Chris Huhne seems to be in a precarious position, after his Eastleigh seat was carved in two, and absorbed into what now look like two quite safe Tory seats.

The changes in England mean other Lib Dems - including rising star Tim Farron - could find themselves with seats which are even more marginal than before. But on a brighter note for the Lib Dems, many of the party's MPs in the south west of England could find themselves with slightly safer seats under the changes.

London is set to lose five of its 73 constituencies. The most interesting battle may be south of the Thames, between two of Ed Miliband's most loyal lieutenants. Tooting MP Sadiq Khan, who ran Miliband's leadership campaign, looks to be in for a territorial scrap with Miliband's former parliamentary aide and Streatham MP, Chuka Umunna. The Boundary Commission has helpfully suggested creating a merged Streatham and Tooting seat.

The Conservatives will lose one of their safest seats in the capital with the abolition of Mark Field's Cities of London and Westminster constituency. After the next election, the bankers and hedge-fund managers of the Square Mile could find themselves represented by the current Labour Islington South MP - and former TUC campaigns director - Emily Thornberry. The new seat will be named The City of London and Islington South.

These proposals by the Boundary Commission in England are only the start of a long process to redraw Britain’s political map. Public meetings will be held across the country in the coming months, where the public - and the existing MPs - can challenge the proposals.

Ultimately Parliament will have to vote on a final electoral map before the next election, a vote which many MPs and pundits now view as being potentially highly divisive within the parties.