Kenneth Clarke has apologised following his comments on rape and rape sentencing yesterday. It wasn't the apology that saved his career, though – it was Ed Miliband.

The moment Miliband called for Clarke to be sacked, Clarke was safe. Sacking Clarke, or shifting him sideways, could have been a fillip for David Cameron. He would have looked swift and decisive. It would have also thrown a bone to the increasingly peeved right of his party, who think that the Tories are going soft on crime. Clarke's Europhilia and liberal tendencies do not make him popular with elements of his own party. Miliband's call for Clarke's head, however, took the option off the table for Cameron. If he had bowed to Miliband, he would have looked spineless.

Instead it looks as if Clarke will survive, if he continues to show suitable contrition. The irony, as my colleague George Eaton points out, is that many in the Labour Party don't want him to go – at least, not thinking from a policy point of view. Indeed, many in Labour seem to agree with Clarke's prison policies, as the New Statesman blogger Dan Hodges points out. Clarke is a liberal and competent minister who is attempting to turn the UK away from its over-reliance on prisons.

In terms of general policy, Clarke and Miliband are not disimilar when it comes to sentencing. Even when writing in the Sun – when a leader of the opposition should be at his or her blustering best on law and order – Miliband called for sentencing reform. He wrote:

Tougher prison sentences aren't always the answer. I think there are times when people get locked up and come out as harder criminals. Some non-violent offenders can be better punished with a tough community sentence, working off their debt to communities over months rather than getting off with a few days in jail.

Clarke is attempting to enact this type of policy. If he goes, the policy goes with him. What he said was stupid and betrayed a depressingly common prejudice that some rapes are not "serious" or violent, and he was right to apologise. But Miliband should not have called for him to go.

Even if Clarke were to be sacked and a more authoritarian justice secretary replaced him, Cameron would have looked weak briefly, but at what cost to Miliband and Labour? If Dominic Grieve had come in and started hammering criminals, there would have been no boost for Labour. No one – least of all Conservative politicians – loses votes for locking too many people up.

Yesterday was bad politics by Miliband. As Steve Richards points out in the Independent, a "leader of the opposition cannot call on ministerial resignations too often". With this in mind, Miliband has played his hand too early. Clarke won't go – and Miliband shouldn't want him to.