A Government review into the UK's nuclear deterrent options will show alternatives other than a like-for-like replacement of Trident exist, Danny Alexander has said.
The chief secretary to the Treasury said the two-year review, expected to be published next month, does not come to any conclusions but will show there are choices available to the country.
He said these alternatives would help nations move on from the "Cold War postures of the past".
The Liberal Democrat party leadership is against the £20 billion like-for-like replacement of the continuous at-sea nuclear deterrent and demanded an official review into other options when the coalition with the Conservatives was formed.
But the report is expected to show that the alternatives are either impractical or more expensive.
Alexander, who has been leading the review for the last nine months, told BBC One's The Andrew Marr Show: "That review was completed two weeks ago and submitted to the Prime Minister and Deputy Prime Minister.
"The question it is trying to answer is, 'Is complete renewal of Trident and the way previously planned the only way to protect our country in the future?'.
"While the review doesn't come to any conclusions, I think when we publish the results in a few weeks time people will see that there are choices available to this country.
"There are alternatives where we can - as President Obama said in Berlin last week - move on from the Cold War postures of the past and try and set out a new future for this country with a deterrent that is credible, but where this country can play a role in supporting disarmament in future."
Research for a parliamentary committee last week found more Lib Dem voters back replacing Trident if a cheaper alternative is not viable than those who would oppose it.
In a series of polls for the Public Administration Select Committee, Lib Dem backing for four new submarines reached 47% after voters were shown information about Trident and asked to decided what they would support if the Government rules that alternative systems are not an option, while 42% wanted disarmament.
The research by YouGov was commissioned to look into deliberative polling, which repeatedly asks voters the same set of questions but presents them with additional information and arguments throughout the process.
MPs urged the Government to use the system to build up a more accurate picture of voter beliefs which could then be used to influence policy-making.
John Woodcock, MP for Barrow where Britain's submarines are built, said: "The Liberal Democrats now seem to want to change the way the UK deploys the nuclear deterrent instead of scrapping Trident itself: - that is a big climb-down after years of peddling the fantasy that we could save billions by switching to some kind of mini-deterrent.
"But after wasting taxpayers' money on a review that has shot their preferred Trident alternative to pieces, few will take the Liberal Democrats seriously if they claim Britain could make do with a part-time deterrent that is not operational round the clock.
"Ending Britain's commitment to continuous at-sea deterrence - having at least one submarine carrying the deterrent operational at all times - would save relatively little money and make the UK much more vulnerable in the event of a nuclear threat in future decades."