The decision about replacing the Trident nuclear deterrent system will be taken with "proper respect" for parliament, Jack Straw has insisted.
The leader of the House of Commons said the government would introduce a white paper discussion by MPs, after chancellor Gordon Brown's announcement that Britain should maintain the deterrent in the long-term.
His comments, although merely repeating Labour's general election manifesto pledge to keep an independent nuclear deterrent, have provoked a storm of controversy, particularly within the Labour party where many are opposed to nuclear weapons.
Opposition parties have also expressed concern that the decision to replace Trident, which could cost between £12 billion and £25 billion depending on who is arguing the case, would be taken without proper parliamentary scrutiny.
Downing Street promised there would be a "proper discussion", adding: "Governments have to look at the options, assess the different options, set out those options properly so people understand why decisions are made, and the government will do that."
However, it refused to say whether there would be a vote on the issue. Questioned on the matter this lunchtime, Mr Straw told MPs: "Decisions on Trident have yet to be taken.
"When they have been they will be put to parliament in a white paper. Mr Speaker, at the moment I cannot envisage the most appropriate form of debate that will take, but it will be in a form that shows proper respect for this House."
Trident retires in 2024 and ministers have previously said a decision on whether or not to replace it would have to be taken in this parliament.
But Mr Brown's statement has provoked fury among his own party, with some now questioning whether they could still support him to succeed Tony Blair.
However, many see the announcement as a strategic move, to prove that the chancellor is as tough on defence as the prime minister, and also to distance himself from the left of the party who may seek to reverse Mr Blair's reforms once he leaves power.
An early day motion put by Labour MP Neil Gerrard earlier this year arguing against replacing the nuclear deterrent programme has attracted 47 signatures, and several Labour backbenchers have already come out in opposition to Mr Brown's plans.
"The manifesto commitment was to retain Trident. Many of us thought this somewhat foolish but that if we left it there it would die in its boots and we would not commit to replace it," left-winger Alan Simpson told Newsnight.
"The notion of saying we will put £25 billion into a weapons system we have never really known how and when we would use it, when we cannot afford to pay people's pensions.what on earth are we doing?"
Conservative MP James Arbuthnot told the same programme it would be "pretty unthinkable" not to have a vote on the issue.
More than 201 MPs have put their names to an early day motion by Labour MP David Chaytor calling for ministers to publish a full consultation paper on Trident before any decisions are taken, and 122 have signed another calling for a vote on the issue.
Last night, however, shadow defence secretary Liam Fox suggested Mr Brown's announcement was nothing more than an attempt to boost his image as a statesman saying: "His words are exactly the same as those in the 2005 manifesto and are not new.
"The chancellor is reheating an old pledge to retain the current nuclear deterrent, but he is not committing to replacing the independent nuclear deterrent when it reaches the end of its current life. Yet again Gordon Brown is playing fast and loose with the truth."