In the wake of another special-election drubbing in Britain, questions are again being asked about the future of Conservative Prime Minister David Cameron. While he has no shortage of critics on the left, more significant is the growing dissent within his own party. If the knives are not quite out for Cameron yet, some of his MPs are certainly hovering close to the cutlery.

The latest special election (they’re called by-elections in the UK) was won by the Liberal Democrats, the Conservatives’ partners in the coalition government. The Lib Dem victory was not unexpected; the problem for Cameron is that his party was beaten into third place by UKIP, the anti-European Union, tough-on-immigration party that has been attracting growing numbers of former Tory voters.

Meanwhile, Britain’s economy stubbornly refuses to grow, and although unemployment has been falling, so have been living standards as stagnant wages are outstripped by inflation. The pound is close to recent historic lows against both the dollar and the euro, with both inflation and the fall in sterling exacerbated by the Bank of England’s ongoing policy of using quantitative easing — printing money — to try to jumpstart the economy.

Cameron and Chancellor of the Exchequer George Osborne have failed to bring borrowing under control, and last month the UK lost its AAA credit rating with Moody’s. The downgrade isn’t the end of the world — Britain’s borrowing costs remain low, and after the U.S. was downgraded by Standard & Poor’s in 2011, its borrowing costs fell — but the downgrade is a political setback, if not a serious economic one.

Increasingly, Cameron is under pressure from many in his party to adopt more traditionally Tory policies on the economy, public spending, and immigration ahead of the 2015 general election. Not only, goes the argument, are these policies necessary in their own right; they’ll also neutralize the UKIP threat, and prevent a repeat of the 2010 election when UKIP is widely thought to have denied the Tories an outright majority by splitting the small-c conservative vote in marginal seats.

Responding to the latest setback, Cameron has insisted he will not “lurch” to the right, although in the run-up to last week’s contest he was showing signs of doing just that with talk of curtailing immigrants’ access to benefits and healthcare — precisely the sorts of issues on which he’s been outflanked by UKIP. His detractors, however, suspect it was only talk, designed to steal UKIP’s thunder.

Cameron’s ministers have also been floating policies designed to win back lost voters, notably the withdrawal from the jurisdiction of the European Court of Human Rights. The Court has made a habit of preventing Britain from deporting suspected terrorists on the grounds that they might be tortured, and from deporting foreign criminals because it would breach their “right to a family life.”