Tony Blair has promised MPs a full debate on the issue and reportedly told a cabinet meeting last week that he wants the debate to begin quickly "because a decision needs to be made".
The Sunday Times November 19, 2006
The government has promised to launch the debate with a white paper outlining options, but defence sources said the key decisions have in effect "been made".
The Trident system, which entered service in 1994, has to be replaced in the mid-2020s. Ministers have argued that the length of the procurement process requires a decision now.
But Whitehall sources say the timing has more to do with Blair's determination to ensure Britain is committed to a long-term nuclear deterrent before he stands down as prime minister next year.
"There will be massive opposition to this within the party," said Paul Flynn, a Labour backbencher. "If you talk to cabinet ministers privately they don't even try to defend it."
Critical to the debate will be the ageing British warhead, with doubts on whether it will detonate. Development of a new warhead would breach nuclear non-proliferation agreements.
The Liberal Democrats said government claims that it was not developing a new warhead were impossible to believe.