Brown to cut UK's Fleet of missile-carrying submarines.

From the BBC NEWS

The prime minister is to tell the United Nations that he is willing to cut the UK's fleet of Trident missile-carrying submarines from four to three.

Gordon Brown will make the offer at a meeting of the UN Security Council on halting the spread of nuclear weapons and reducing existing stockpiles.

The proposed cuts come as the government searches for ways to reduce the massive deficit in public finances.

However Number 10 said keeping the UK's nuclear missiles was "non-negotiable".

At the UN meeting, Mr Brown will call for all nations to come together to achieve the long-term ambition of a nuclear-free world.

Nuclear warheads

He will say: "If we are serious about the ambition of a nuclear-free world we will need statesmanship, not brinkmanship."

BBC defence correspondent Nick Childs said Mr Brown would hope it will be seen as an important gesture in a much bigger global disarmament deal, but the key to the process would be the actions of the United States and Russia.

David Miliband: "The long-term aim is a world free of nuclear weapons"

US President Barack Obama is chairing the meeting as part of the process of drawing up a replacement for the Non-Proliferation Treaty, designed to stop countries developing nuclear weapons.

He has said he will try to negotiate with Moscow to reduce US and Russian nuclear warheads - which make up the vast majority of the world's total - from more than 2,000 each to 1,500.

The UK government says it has cut its stockpile of Trident warheads from 200 to 160 but many Labour MPs would like it to scrap the weapons altogether.

But the Liberal Democrats are the only party to say they would not seek a "like-for-like replacement" for Trident - which is due to need replacing by 2024.

Officials travelling with the prime minister warned that reducing the number of submarines, which are based at Faslane on the Clyde, from four to three would not result in a 25% cut in cost.

The government estimates the cost of renewing Trident at about £20bn but Greenpeace says it could cost £34bn and, once lifetime running costs are included, would cost nearly £100bn in total.

Professor Ron Smith, a defence economist at Birkbeck College, told BBC Radio 4's Today programme that going from four to three submarines would probably have little effect on Britain's nuclear capability.

"The idea of having four of them is essentially you have got one spare as insurance," he said.

He added that the cost of replacing Trident was "very unclear" but working on the £20bn estimate, losing one submarine would only save "a couple of billion" in about 2020 as there were a lot of fixed costs upfront and each boat cost less to build than the last one.

Downing Street says maintaining an independent nuclear weapon system is "non-negotiable".

At-sea patrols

Foreign Secretary David Miliband added: "We reject unilateral nuclear disarmament for ourselves precisely because the world cannot end up in a situation where responsible powers get rid of their weapons, but the danger of nuclear proliferation by other powers remains."

Shadow defence secretary Liam Fox said reducing the number of submarines was not a new idea as it was an option set out in the government's 2006 White Paper.

He told the BBC: "If we can maintain our nuclear deterrent and make a contribution to disarmament that's all very well but the prime minister is not planning to reduce the number of warheads from 160 ... merely to have them in fewer submarines."

He said it was "reasonable and sensible" to look at doing that if the technology was available to make it possible.

"The important thing is we maintain our nuclear deterrent and maintain our at sea deterrent at all times."