Brown offered compromise over Trident row

Britain's nuclear weapon system could be slimmed down to reduce the £25bn cost of a replacement to Trident and defuse some of the controversy facing Gordon Brown and Tony Blair.

Mr Brown's hopes of a smooth handover of power from Mr Blair were dented last week when Labour leftwingers reacted angrily to his decision to back a full replacement for the submarine-launched ballistic missile system.

The Commons Defence Select Committee is to offer a compromise today, which could help Mr Brown overcome some of the opposition from his MPs by suggesting a lower capability of nuclear weapon to meet the threat of terrorism, rather than that from the Soviet Union.

The MPs suggested that instead of using four submarines that are constantly on patrol with nuclear weapons, Britain could retain a nuclear system that was not constantly at sea. "In the light of the reduced threat we currently face, an alternative possibility would be to retain a deterrent, but not continuously at sea," said the MPs' report.

They strongly hinted that the Cabinet could also put off the hard decisions by following the Americans in extending the life of the US-designed Trident submarines and updating the Trident II D-5 long-range ballistic missiles. That would mean a major refit of the submarines' nuclear reactors, but it could extend the life of the current system until 2042.

It could also mean that the Cabinet will reject a cheaper option of replacing the fleet of four Vanguard class submarines carrying Trident missiles with aircraft armed with nuclear-tippedcruise missiles.

The select committee, chaired by the former Tory minister James Arbuthnot, condemns the Ministry of Defence for refusing to co-operate with its inquiry. The MPs angrily point out that John Reid, then Defence Secretary, promised an open debate but they say the MoD refused point blank to give evidence about the update of Trident.

"We are surprised and disappointed by this refusal," said the MPs. "A genuine meaningful debate is only possible with the active participation of the MoD. The public should know what decisions will be required when they must be taken and implemented, and what factors are driving consideration of the issue now."

The MPs warn that the Cabinet, which has to take a decision in the current Parliament, will have to confront the difficult question over whether Britain still needs a nuclear weapon after the ending of the Cold War. They want the MoD to "explain its understanding of the purpose and continuing relevance of nuclear deterrence now and over the lifetime of any potential Trident successor system".

The Prime Minister confirmed on Wednesday that a decision on whether to replace Britain's Trident nuclear programme will be taken "later this year".

Challenged by David Cameron, the Conservative leader, Mr Blair said that an independent nuclear deterrent was an "essential part" of Britain's defences. He promised to consult fully on the controversial issue but stopped short of offering a Commons vote to settle it.