Military Doubts Fail to Sink £20bn Trident Revamp

The UK is currently committed to replacing the Trident nuclear weapons system at an estimated cost of about £20bn. The decision, which was taken in 2007, provoked the largest revolt among backbench labor MPs since the Iraq war and will see the UK's four nuclear weapons submarines replaced with new boats from 2024.

On top of the £20bn cost of replacing the vessels - one of which will be on patrol at all times - the government has said Trident's annual running costs will amount to 6% of the £30bn total defence budget over 25 years.

The National Audit Office said there were major areas of uncertainty in the budget, adding that there had been insufficient oversight of the costs.

Some retired military figures have expressed concern over the plans. In January the former head of the armed forces, Field Marshal Lord Bramall, backed by two senior generals, argued that the sums spent on replacing the submarines would be better used to buy conventional arms for the forces.

"Nuclear weapons have shown themselves to be useless as a deterrent to the threats and scale of violence we currently face or are likely to face, particularly international terrorism," the group said. "Our independent deterrent has become virtually irrelevant, except in the context of domestic politics."

The government is pressing ahead with the Trident replacement program, but a more conciliatory tone has been struck in recent weeks.

Speaking to scientists and diplomats from 37 countries at Lancaster House in London last month, Gordon Brown said Britain would reduce the number of missile tubes on each new submarine from 16 to 12, and added that if it was possible to reduce the number of UK warheads further, "consistent with the progress of multilateral discussions", Britain would be ready to do so.

Ministers have repeatedly insisted that the government has yet to decide whether to replace its stockpile of nuclear warheads alongside the new Trident submarines. However last year one of the MoD's senior officials told a private meeting of arms companies that the decision had already been taken.

According to the NAO, the new nuclear submarines will need five years to design, eight years to build and two years of post-launch trials. The main contract to build the vessels is expected to be awarded in 2012.