Is it time for David Cameron to start watching for signs his fellow Tories are about to shoot him in the back? The revelation at the weekend that Cameron's former homeland security spokesman Patrick Mercer was one of the Tory MPs calling for a leadership election has tongues wagging at Westminster. The suspicion is that there are at least 14 MPs who've written to the chairman of the 1922 Committee Graham Brady, calling for a direct challenge to David Cameron.
We're a long way from the 46 letters needed to trigger a leadership contest, and most MPs seem willing to give Cameron another six months to turn things around. But that's hasn't stopped the speculation of who else is on the list of plotters.
MPs are being tight-lipped about who the other "kill Cameron" backbenchers are, and the backbench 1922 chairman Graham Brady is practicing the upmost discretion. But piecing together various sources, from the letter signed by backbenchers over Lords reform to Commons interventions and appearances in the media, it's fairly easy to draw up a list of those who could be among the 14 suspected of calling for a leadership challenge.
NADINE DORRIES
Almost certain to be on the list is the Bedfordshire MP whose anti-Cameron soundbites almost warrant an article of their own. From the infamous "arrogant posh boys" quip to the "kill Cameron strategy" remark just last week, Dorries has nothing to lose, and if as expected the PM's boundary changes are truly dead in the water, she'll probably be around in the Commons longer than Cameron will.
ZAC GOLDSMITH
A fairly sure bet for the list is Goldsmith, who has been openly plotting with Boris Johnson about who will succeed Cameron, and even reportedly offered to give up his seat so the Mayor of London could return to Parliament. Although it seems like the issue of Heathrow's future dominate's Goldsmith's thinking, it's the strong language Goldsmith has used - urging Cameron to "come off the fence" over the issue - which suggests an exasperation with the leadership.
DAVID DAVIS
Davis stood against Cameron in the 2005 leadership contest and has been fairly quiet up until recently. But a fortnight ago he used a speech in the City of London to deliver a withering broadside on Tory economic policy and performance. It came the day before the reshuffle and was taken as a sign that something had to be done, and urgently, to turn the party around. Davis wants radical deregulation, tax cuts and the ditching of various "green" taxes which are likely to push up energy bills next year. It wouldn't be all that surprising if he'd written a Kill Cameron letter.
BILL CASH
Someone for whom rebellion comes easy, Bill Cash has been annoying Tory front-benches for so long he was instrumental in John Major's Maastricht difficulties in the early 1990s. Thinks Cameron hasn't gone far enough to neuter the EU's influence over Britain and regularly annoys the PM whenever the subject comes up in the Commons.
TIM YEO
Famous for his "man or mouse" comments over Heathrow, Tim Yeo joined Zac Goldsmith in making the Heathrow row highly personal and as much about Cameron's leadership as the third runway itself. Yeo still chairs the environment select committee and his comments about Heathrow were fairly extraordinary for someone in his position.
STEWART JACKSON
Jackson lost his place as a ministerial aide when he rebelled against the government on an in/out referendum on the EU last year. While others in his position melted away into the shadows, Jackson has become a fairly regular media performer, frequently digging into the leadership.
BRIAN BINLEY
Binley has rebelled a number of times on key votes, and was vocal in calling for George Osborne to be sacked. When Osborne managed to hang on in the reshuffle Binley said it was "a pity". Binley is widely thought to be on the list, not least since he very recently described David Cameron as a "chamber maid" to the Lib Dems.
DAVID RUFFLEY
Said to be unhappy with various aspects of the coalition's agenda, Ruffley is thought to harbour a lingering mistrust of Cameron and his management of the Conservative Party. Ruffley is thought to believe that several key policies have been mishandled by the leadership.
PETER LILLEY
Lilley had hoped to get a job in government when the coalition was formed but has ended up being an overlooked right-wing backbencher. Lilley seemed quite unhappy with some aspects of the reshuffle, including the Ken Clarke's new role. An indpendent voice on the backbenches, Lilley could easily be one of those on the list.
EDWARD LEIGH
Another dinosaur Tory who's been the thorn in the side of successive Conservative governments, Leigh really doesn't care what the leadership thinks of him. From Europe to economic policy, there's plenty for this truculent Tory to disagree with.
MARK RECKLESS
Reckless has rebelled on many of the coalition's key policies, including the tuition fees hike and the child benefit cuts for higher-rate taxpayers. Fiercely independently minded, Reckless' name crops up fairly often when Kill Cameron plotters are discussed.
PETER BONE
This list wouldn't really be complete without Peter Bone, who is among the most independent backbenchers. He really doesn't care what the leadership thinks of him and knows he will never be a minister. Bone makes it obvious he'd rather the Tories had a more right-wing leader (someone like William Hague, perhaps) and although Cameron is cordial in public, there's no love lost between himself and Bone.
CHRISTOPHER CHOPE
Chope was booted off the 1922 Committee during elections in May, which saw modernisers and Cameron loyalists take control of the backbench executive. At the moment Chope is incensed about plans for gay marriage, but Europe, the economy and anything which panders to the Lib Dems also rile this veteran MP.
GRAHAM BRADY - THE MAN WHO GETS THE LETTERS
The chairman of the 1922 Committee is being incredibly tight-lipped about the leadership contest speculation. But it's well-known that Brady is fervently eurosceptic, a supporter of grammar schools and no fan of the Lib Dems. He recently suggested the coalition might break-up as much as a year before the scheduled date of the next election in 2015. Since the elections in May the 1922 has been more balanced in favour of loyalists and modernisers, with the kinds of people listed above marginalised. This might explain in part why the malcontents have opted for this new strategy to undermine David Cameron.