Two North East politicians broke ranks with party colleagues to join a small number of MPs who voted to abandon plans to renew the Trident nuclear deterrent.
Grahame Morris, Labour MP for Easington in County Durham, and Ronnie Campbell, Labour MP for Blyth Valley in Northumberland, backed a Commons motion which said plans to spend more than £25 billion on a new Trident system should be scrapped.
But they were in a clear minority, which just 37 MPs voting for the motion and 364 voting against.
Critics say the true cost of the scheme to the taxpayer could be as high as £100 billion.
Speaking in the House of Commons, Defence Secretary Michael Fallon told MPs that the cost of replacing four ageing Vanguard-class submarines used in the Trident system would be £25 billion but “it is not possible” to confirm the full cost until next year.
A motion stating that “Trident should not be renewed” was proposed by the Scottish National Party and Welsh nationalist party Plaid Cymru, and backed by the Respect and Green party MPs in the Commons.
Conservatives, Labour and the Liberal Democrats officially opposed it, but a small number of MPs from all three parties voted for the motion.
Mr Morris said: “I want a safer world moving towards nuclear disarmament. Replacing trident will undermine the UK’s moral authority when seeking to restrict nuclear proliferation by other countries.
“Nuclear weapon address the security concerns of the past and we must move beyond a cold war mentality.
“We must adapt to meet the new security challenges of the 21st Century, such as climate change, pandemics, organised crime, cyber warfare and terrorism.”
There were better ways to spend public money, he said.
“In a time of austerity when the Government are making damaging cuts to our armed forces as well as cutting public services back to the level of the 1930’s, we cannot justify spending in excess of £100 billion on a new trident system that will do nothing to improve the security or defence of the UK.”
MPs who voted against the motion included Sedgefield Labour MP Phil Wilson, who said that he had joined the Campaign for Nuclear Disarmament at the age of 20 but soon left.
Speaking in the Commons, he said that he wanted to see an end to nuclear weapons but did not believe the UK would achieve that by simply giving up its own weapons.
“A world of peace and a world free of nuclear weapons and of the threat of nuclear annihilation are the principles and the goals we should be pursuing,” he said.
He added: “If we do not take ourselves seriously, no one else will. In a globalised world the trick is not to be small and make ourselves even smaller, but to walk tall and be part of, not against, something greater than ourselves.
“As a consequence, Trident or its equivalent continually at-sea as a deterrent is the burden that we need to carry until multilateral disarmament opportunities arise. As I learned in the early 1980s, wishful thinking gets us nowhere.”
Defence Select Committee chair Rory Stewart said the decision was far too important to be a question of economics, adding: “This is a question of Armageddon.”
The Tory MP also argued that it was unwise to change the nature of Britain’s deterrent when the Government is unsure of the threat posed by Russia.