Britain will announce plans tomorrow to order a new generation of nuclear-armed submarines but will say the fleet could be cut to three from four, newspapers reported today.
In a gesture to nuclear opponents in the Labour Party, Prime Minister Tony Blair will also announce further cuts in Britain's nuclear warheads, already reduced by a third to fewer than 200 since he came to power in 1997, the Observer said.
Britain's existing nuclear defence, consisting of Trident missiles carried aboard four Vanguard-class nuclear-powered submarines, will remain in service until 2024.
A spokeswoman for Blair declined to speculate on the content of the policy document on nuclear weapons that Mr Blair will unveil with a speech in parliament tomorrow afternoon.
The government says it must take a decision now on whether or how to replace Trident - at a cost of up to stg£25 billion pounds (€37 billion) - because of the time needed to design and build new submarines.
However, Mr Blair will face a battle convincing some in his own party that there is a need for a costly new nuclear deterrent. Some say he is trying to rush through a decision before he leaves office next year.
"There is no policy imperative for a decision on Trident to be taken now," John McDonnell, a left-wing MP who will challenge finance minister Gordon Brown for the party leadership when Blair steps down, said in a statement.
Mr Blair is expected to be able to stave off a Labour rebellion with the backing of the opposition Conservatives.
The Sunday Times said the government will say it intends to build the new submarines in Britain provided British industry offers the right capability at the right time and price.
An executive of BAE Systems, Britain's major submarine contractor, said last month it would have a catastrophic effect on the country's skills base if the government did not order a new class of nuclear submarines.