Cameron leaps into the unknown Let us begin with what David Cameron can't know, and therefore can't control, in the wake of his speech on Europe. He can't know whether his plan to reform the EU and repatriate powers will be acceptable to other member states. Indeed, the prime minister can't know whether he will be able to reach any agreement at all. He therefore can't know whether he will recommend a Yes or a No vote in the in-out referendum that would follow from a Conservative majority in the 2015 UK general election. Mr Cameron also can't know how his party would react to either recommendation. This problem will be heightened if he advocates a Yes vote, since up to half of his party members, perhaps a quarter of Conservative MPs and as many as nine Tory cabinet members want out of the EU altogether. And that's presuming he wins a majority. He can't know whether the Liberal Democrats, the minor party in the current UK coalition, will accept his insistence that his Europe plan marks a "red line" in any future negotiations to form a government. It follows that if he sticks to his last in any such talks in 2015, he could be pitched out of Downing Street. Ironically, then, his speech lessens rather than boosts the chances of his re-election as prime minister. So why has this cautious politician, naturally restrained in temperament and outlook, taken such an extraordinary gamble, risking the very unity and future of his party? There is no great mystery about the answer. It is the only way he can think of to get the eurosceptic monkey off his back. Almost half his backbenchers voted for an EU referendum last year. The rightwing newspapers have clamoured for one. In some opinion polls, the UK Independence party has overtaken the Lib Dems as the third party of British politics. With the odds on him winning the next election long, the prime minister has decided to buy himself time to get back into the game. His gambit relies on the eurosceptic backbenchers - the hardcore of whom number more than 80 - freeing Mr Cameron to concentrate his energies on the bread-and-butter issues that matter most to voters: living standards, jobs, the health service, reducing crime. The optimistic view is that the rapturous reception his speech gained from the eurosceptic press and most Conservative MPs will set the tone. Certainly, the prime minister has turned the tactical tables on his rivals. He has shot and stuffed Ukip leader Nigel Farage's referendum fox. More importantly, he has cast himself as a generous-spirited democrat and both Nick Clegg, Lib Dem leader, and Labour's Ed Miliband as elitists terrified of public opinion. Smart tactics. But will they work? Mr Cameron is hoping that his eurosceptic MPs will allow him a leisurely timetable in which to draw up his repatriation-of-powers plan. The government's review of the "balance of competences" - its audit of what the EU does and how it affects Britain - won't be published in one fell swoop. Rather, it will be issued in stages between now and the next election. The prime minister's plan will be to dovetail his own manifesto plans for the next election with this process, which would allow him not to reveal his shopping list until spring 2015. Will he succeed? The pessimistic view is that concessions to the eurosceptic hardcore only encourage them to raise their demands, and that they will soon be back with more. Much, therefore, depends on the one consequence of his speech that Mr Cameron can know - namely, exactly which powers he will seek to repatriate. It could be a very limited list: safeguards for the City, the end of the working time directive, and precious little else. Or it could be almost unlimited: in effect, the demand of the less pliant end of the eurosceptic movement for "single market or out." We simply don't know - and nor at this stage, I suspect, does Mr Cameron. He grasps that his party wants maximalist demands and his European partners minimalist ones: he will therefore want to preserve maximum flexibility. My hunch is that his tactics will work, at least until the run-up to 2015. Whether his strategy will do so is another question - if, that is, his gamble can really be described as a strategy at all, rather than a variant on that old Tory tradition: muddling through. The writer is a former Conservative MP and executive editor of Conservative Home