Has Ken Clarke opened the door to 'alternatives' to Trident?

Is it me, or has Ken Clarke has just come perilously close to breaching Conservative policy on Trident?

In a BBC News Channel interview, Mr Clarke, the shadow business secretary, said the Conservatives would retain the British nuclear deterrent. So far, so uncontroversial.

But he then opened the door to looking at cheaper alternatives to a direct replacement for the Trident system.

He said:

“We can look at alternatives. If we can find a less costly way of delivering it, that’s fine. I’m not convinced there is one.”

For the record, the Conservative manifesto states:

“We support the decision to renew Britain’s submarine-based nuclear deterrent, based on the Trident missile system.”

The Liberal Democrats, meanwhile, have said that they would keep a nuclear weapon, but ruled out a “like-for-like” Trident replacement. Instead, they say, Britain should, er, look at cheaper alternatives… Hmmm.