David Cameron can't say it, but the PM is set on another coalition No wonder Mr Cameron sought to bind the referendum on AV, which the Liberal Democrats wanted, with a smaller House of Commons, which he wanted - because the latter would significantly have reduced Labour's advantage. The deal with Nick Clegg's party collapsed after Tory backbenchers sank Lords reform and the Liberal Democrats, in consequence, sank the cull of MPs. The Conservatives must now fight the same seats at the next election as they did at the last one. Cameron needs a lead of between seven to 10 poll points to scrape a bare majority. Conservative morale is much revived recently. The benefits cap is in place. Abu Qatada has been deported. There is an EU referendum Bill to cheer up Tory MPs and activists. Ed Miliband and Labour have been damaged by the revelations about Unite and Falkirk. Above all, the economy is slowly recovering. No wonder the Prime Minister's recent charm offensive towards Tory backbenchers has met with a more enthusiastic reception than some previous attempts. One opinion poll even found that the two parties" ratings were even. But here's the rub. Level ratings wouldn't come close to delivering Mr Cameron a Commons majority. Punch that poll's numbers into the Electoral Calculus website, and they leave Mr Miliband short of a majority by only five seats. Such is the awesome advantage that the present system hands to Labour. Now imagine the Prime Minister's thoughts as he mulls this cheerless landscape for his party. He can do the calculations as deftly as anyone. He knows that Left-wing Liberal Democrat voters have abandoned Mr Clegg's party and are backing Mr Miliband's. He knows, too, that Ukip will damage the Conservatives more than Labour if it polls below 16 per cent in 2015 - and that, for better or worse, its vote share is likely to come in below that figure, but above the 3 per cent it gained in 2010. In a perfect world, the PM might yearn for the landslide majorities of the Thatcher era. But in this fallen one, he knows that they are psephologically impossible. This leaves him a stark choice. Should he strain for the bare Tory majority which is scarcely possible, or plan for a more practicable outcome - a second coalition? There can be no doubt what his decision will be - indeed, what it already is. On The Andrew Marr Show on Sunday, Mr Cameron protested that he wants and can gain a majority. Frankly, both claims were from the Pinocchio school of truth-telling, fit only to make his nose grow and the angels weep. He was talking nonsense. He knows it. You know it. Nick Clegg knows it. And above all, Conservative backbenchers know it. They grasp that for the two long years between now and the next election, the Prime Minister will continue to say one thing while actually planning another. The movement towards a second coalition will be undertaken to a kind of two-step dance, as Mr Cameron moves first away from Mr Clegg, and then back towards him. It is in neither leader's interests for the Coalition to break up before the 2015 election campaign: this would undermine the picture they want to present of two parties working together for the national interest. But the ties that bind them together will be loosened. Watch for Tory MPs moving Commons motions and Bills proposing a tougher benefits cap, a lower immigration limit, an end to ECHR membership. The Prime Minister will back such proposals vigorously both before and throughout the 2015 campaign - on the hustings, in interviews, in the leaders" debates, in the Conservative manifesto. But what he does will be watched as closely as what he says. Will the party really strive to turn David Laws out in Yeovil, when his offices could be integral to a second coalition? Will the manifesto contain Liberal-Democrat-friendly policies, such as a further rise in tax thresholds? Will Mr Cameron risk a break in relations by throwing the rhetorical kitchen sink at Mr Clegg's party? Let us presume that election day, after the ups and downs of campaigning, yields a result not unlike the last one. One can already hear the Prime Minister's pitch to the 1922 Committee. The Liberal Democrats are demanding much less than in 2010 (he will say). This time, they only want proportional representation for local government. We can offer a referendum on that, surely, knowing that we'll win again? The last coalition delivered Conservative policies on crime, on the welfare cap, on immigration control, and on tax: so can a second. Furthermore (he will add), the promised EU referendum will take place. Are we really going to turn this glittering prospect down, and put the discredited Miliband into Downing Street? Let me now move out of Mr Cameron's voice, and back into my own. I think that pitch doesn't sound at all bad. I suspect it would convince - that his party would wave Mr Cameron back towards Downing Street, and that the second step of the dance would thereby be complete. This exercise in dissembling may not reflect well on Mr Cameron. But if you think matters through, can you really blame him? In plain terms, after all, his choice in this circumstance would be between coalition and a cushy Commons majority of 80 or so, or a minority government without one - leaving him at the mercy of Adam Afriyie and the 20 or so backbenchers who want rid of him. All this may never happen. Mr Miliband may well be the next prime minister after 2015. But it's far from impossible that, come 2020, Mr Cameron will have equalled Margaret Thatcher's tenure in Downing Street - without having won even a single election to compare with her hat-trick. Paul Goodman is editor of ConservativeHome