Leading article: Too many changes of mind from the Prime Minister

There was something refreshing about the way that David Cameron seemed unafraid, when he first became Prime Minister, to admit that one of his policies might have been wrong and then change it. It stood in stark contrast to the rigidity of the era in which Conservative party policy was governed by sclerotic slogans like "The Lady's not for turning". But you can have too much of a good thing.

Mr Cameron stated yesterday, as his government made the latest in an extraordinarily long list of U-turns – this time over the sentencing of convicted criminals – that he did not for one minute think it weak for a government to listen to the public and then change its mind. But this looks less and less so.

From the outset the Prime Minister's strategy was a return to Cabinet collegiality. He would allow ministers a freer rein to develop policy with him acting as a chairman of the board on wider policy. But the U-turn on sentencing comes just a week after one on the controversial NHS reforms. Earlier in the year he dropped plans to sell off England's forests. There have been U-turns on grammar schools, a free book scheme, free school milk for the under-fives and in funding for school sports. The Conservatives have reneged on their commitment to restore weekly bin collections.

Some of this may have been desirable. But there has been too much of it. It has come to seem that Mr Cameron's real strategy is to allow ministers to run policies out into the public arena and then haul them back if the public or the red-meat press protest too much. As a result the Government appears to be stumbling from one crisis to the next.

On crime and punishment it has left us with exactly the wrong policy. The reforms set out by the Justice Secretary, Ken Clarke, were largely a step in the right direction. It is true that Mr Clarke was uncharacteristically maladroit in presenting them. But the political hoo-haa which surrounded his remarks on rape has had regrettable consequences. The Clarke reforms would have reduced our oversize prison population, created more scope for rehabilitation of the remaining prisoners, increased discretion for judges, made the administration of justice more cost-effective and created an incentive for prisoners to plead guilty earlier, reducing worry and distress for victims.

All that has been lost, as has even the incentive to plead guilty to less serious offences. It has been replaced by a lot of populist "tough on crime" rhetoric on knives, squatting and a pointless restatement of the existing law which allows property-owners to use reasonable force against burglars. All this will increase the prison population, and its cost, and leave more rapists wandering the streets. It will bring even deeper cuts to legal aid for the poorest and curtail the ability of the probation service to supervise ex-offenders in the community and keep them from returning to custody.

Running scared, Mr Cameron has shown himself to be a political coward who prefers being popular to doing what is best for the nation in the balance between protecting the public, deterring criminals and reforming offenders. But other politicians are little better. Ed Miliband, in an opportunistic attempt to score points against Mr Clarke, has committed Labour to a bad policy on prisons. And Nick Clegg, who went into the election pledging to abolish short prison sentences, has immersed himself in complicit silence.

In the months ahead more and more of the Coalition's rhetoric on public spending cuts will meet the immovable object that is fiscal reality. If Mr Cameron continues to respond with such "political flexibility" it will increasingly be seen as a sign of weakness rather than strength.