SINCE Ed Miliband went up in everyone's estimation by suggesting that he believes in One Nation Conservatism, David Cameron could try devoting his conference speech to praising Clause Four.

It is true that "common ownership of the means of production, distribution and exchange" has not hitherto been seen as a terribly Conservative policy, but then nor has borrowing money hand over fist to bail out private firms, increasing taxes on the middle classes and running a public sector net debt of more than £2 trillion (if one includes the financial interventions in the banks).

This conference may be the last opportunity – if that moment has not already passed – for the Prime Minister to persuade the voters that he knows what he's doing, though I wouldn't like you to take it from that statement that I am convinced that he does know what he's doing.

Mr Cameron is generally reckoned to be a better performer when forced into a corner, which is just as well for him. He has, too, a couple of electoral advantages that make his position not yet hopeless; those are the Liberal Democrats and Labour.

The likelihood must be that the Conservatives' Coalition partners will do extremely, perhaps terminally, badly at the next General Election. Nick Clegg has alienated many of his previous supporters and, even if the economy is seen to be improving by 2015 (an unlikely eventuality, for reasons I'll get to in a minute), any electoral credit which might accrue will be notched up in the Tories' political stock, not his. It's hard to imagine the LibDems getting anything out of their time in office, other than trounced. And Mr Clegg having had the chance to swank about a bit and make it into the pop charts.

Labour is ahead in the polls, but not as far as it should be. The Tories are actually less far behind now than both Margaret Thatcher and John Major's governments were before they won outright. And Mr Miliband's speech, though the best performance he has yet given, has not really changed the public perception of him as a loser: the latest polls suggest that 57% still think it's unlikely or very unlikely that he'll become Prime Minister.

That could change, I suppose. But not easily, without two things which are essential if Labour is to been seen as an improvement on the current mob. The first is an admission that the party made mistakes which were largely responsible for the current predicament, and that will be a difficult trick to pull off. Acknowledging that Gordon Brown was the worst Prime Minister since Edward Heath – and perhaps even worse, making him a strong contender for worst ever – is doubly awkward, since Mr Miliband and Ed Balls were instrumental in forming and implementing his catastrophic policies.

The second is coming up with policies that differ from both this Gvernment's and the last one's, and which might actually improve matters. Despite the Labour leader's speech, that is a near-impossibility, because it would require a fundamental rethink of the party comparable with Disraeli's reinvention of the Tories, which Red Ed may like alluding to, but which he has no real hope of emulating. Simply put, a party which has as its central purpose the redistribution of wealth and expansion of the public sector has nothing to offer at a time when those are the cause of our problems.

Mr Cameron, by contrast, at least has access to such a course of action. All he needs to do is start doing all the things which he says he is doing, but in fact is not, and stop doing most of the things which he is doing, but says that he isn't.

At the moment, the Conservatives are receiving all the opprobrium which one would expect when a government is engaged in a ruthless austerity programme, without any of the concomitant benefits which would come if they were in fact cutting spending. That is why the economy is unlikely to show much improvement by the time of the election, because the Prime Minister and the Chancellor have squandered the political capital and room for manoeuvre which new governments enjoy.

The election result may not have been an outright mandate for the Tories, but there was no doubt that the voters had conceded that the country needed fairly unpleasant medicine, which would involve major cuts in the public sector, and a reduction in borrowing. The time to do that, therefore, was at once, while there was a degree of acceptance of the necessity of the measures, and also the prospect that the cure could be seen to be working by the time the General Election rolled round again.

Instead, the Chancellor borrowed more, and hosed down the banking sector with more than £375 billion of credit, in the form of Quantitative Easing, which achieved precisely nothing. Meanwhile, the list of things which were going to be cut, and which the Government subsequently decided against, is depressingly long: selling some forests, cutting free milk, removing child benefit from the rich, taxing pasties, housing benefit cuts, World Service funding, a tax on static caravans-

Whether those policies, subsequently abandoned, were desirable, or even saved much money in the grand scheme of things, doesn't matter. The point is that if the Government can't manage such relatively minor economies, it is no surprise that it has failed to produce real cuts in public spending, or that it continues to run up yet more debt.

Yesterday's disclosure that public sector workers in Scotland are paid 42% more than their counterparts in the private sector shows that no serious moves towards cuts have begun. It can't be said too often. Public spending is up; indeed, it is the highest ever.

Nor can the Tories blame the LibDems; these reversals are entirely due to incompetence (though if any of them had been undertaken to please Mr Clegg or Vince Cable, that would be almost as damning in itself).

Mr Cameron has one slim chance of surviving as Prime Minister after 2015. But it involves trying genuinely Conservative policies, not talking about them and doing the opposite.