Coalition in dodgy waters on decision to delay Trident replacement?

The BBC reported on 16 September 2010 that a row had broken out about the decision to delay Trident replacement. Will the Coalition seriously consider such a delay, and what would be the consequences for the Coalition parties? The consequences for costs — if it is a delay and not a cancellation — would be significant: the programme would require more money, more quickly, to get the new submarines built in time.

That is, if the government is not backtracking on their agreed 'minimum continuous deterrence' principle.