Defence Secretary: Downgrading nuclear weapons 'naive'

Defence Secretary Philip Hammond says it would be "naive" not to have a like-for-like replacement of the UK's Trident nuclear weapons system.

A Lib Dem review of alternatives is set to favour cutting the Vanguard missile-carrying submarines from four to two.

The Lib Dems say the existing system was designed for the Cold War era.

Mr Hammond said it was not possible to predict future threats and that "we need a deterrent system that will deter".