 What's the public mood?  In a recent YouGov poll, only two per cent of voters thought the economy was in good shape. More people believe Elvis Presley is alive. In this climate, any kind of optimism is a tough sell, but David Cameron used his speech to claim that Britain's best days lie ahead.  I believe him, but the mountain top looks a very long way off. Sir Mervyn King warned on Thursday that we're about to walk through a valley as deep and arduous as the Depression of the 1930s. In a week when Greece missed its deficit targets, a French-Belgian bank collapsed and Italy was downgraded, there is mounting evidence that the world is back at the edge of an economic cliff. If Europe goes over the precipice, it's hard to believe that Britain won't follow.  What do the Tories want us to do?  Some want the Government to take decisive action to pull Britain further away from the danger zone - ie, Europe. Others fear any rapid change of direction might create new forms of instability.  at conference, the leadership appeared to side with the second camp. The message was simple: we are not panicking, and neither should you. Cameron's message to the nation was that he had set a course and would stick to it.  What is that course?  Sticking to his plan to eradicate the deficit by the end of the parliament. a U-turn would mean that no one would ever believe him again. Twenty years after the Tories' reputation for economic competence was ruined by the ERM debacle, it would be wrecked again. Labour likes to claim that Cameron's deficit plan is ideologically driven. They're wrong: it's the minimum necessary to put Britai 