DEPUTY Prime Minister Nick Clegg has insisted the country can be kept safe without a Cold War-era nuclear weapons policy which involves being able to "flatten Moscow at the push of a button".

Despite opposition from former defence chiefs, the Liberal Democrat leader claimed there were "plenty of very senior military people" who agreed with his opposition to the like-for-like replacement of the submarine fleet carrying the Trident missiles based on the Clyde. The LibDems have called for an end to the round-the-clock patrols by nuclear missile submarines.

But their Tory partners poured scorn on a "part-time deterrent" while No 10 made clear that David Cameron remained committed to the continuous-at-sea deterrent.

Mr Clegg defended his party's position in the wake of a review, led by LibDem Cabinet minister Danny Alexander, into alternatives.

He said: "The big threat is not the old Cold War threat, but is stateless groups, is terrorist groups, is people getting hold of makeshift nuclear bombs.

"So, then the question is does the kind of equipment and the design of the nuclear system we have, which was for a different age, are there options for slimming it down or changing it such that it can meet security needs?

"You're quite right our first duty is to keep us safe, but which is more appropriate to the threats we face in this modern world? There are ways to keep this country safe but not on the basis you need every second of every day, 365 days to be on a hair trigger to flatten Moscow at the push of a button."

The review was ordered by Mr Cameron and Mr Clegg ,reflecting the LibDems' wish to find a cheaper alternative to the ageing submarines.