Prime Minister Theresa May on Monday urged British lawmakers to back the renewal of Britain's submarine-based Trident nuclear missile system to deter "serious threats."
"We cannot abandon our ultimate safeguard out of misplaced idealism. That would be a reckless gamble," May told parliament, which was expected to support her by a large majority despite opposition from the Scottish National Party and some Labour lawmakers.
"There is a continuing risk of further proliferation of nuclear weapons," she said. "We need to be prepared to deter threats to our lives."
May warned the 58 SNP lawmakers that, through their planned vote against Trident, they "will be voting against jobs for Scotland."
Citing an estimated initial cost of 35 billion pounds (41 billion dollars) for replacing four submarines over the next 35 years, she argued that continued possession of nuclear weapons was also crucial to preserve Britain's global military status.
"Abandoning our deterrent would not only undermine our own security but also that of our NATO allies," May said.
The GMB, one of Britain's largest trade unions, backed the call to renew Trident "to give stability and security to workers and industry."
The largest opposition party, Labour, supports the renewal of Trident but Labour leader Jeremy Corbyn wants Britain to scrap its nuclear weapons, and he has give lawmakers a free vote on Monday.
"I do not believe the threat of mass murder is a good way of dealing with international relations," Corbyn told parliament.
Many Labour lawmakers are expected to support May's motion in the vote late Monday, but others plan to abstain or vote against it.
May's Conservatives have a small parliamentary majority and few, if any, of its lawmakers are expected to vote against the renewal of Trident, making vote in favour of renewal a formality.
In a YouGov survey of 1,631 people, 44 per cent of respondents agreed that Britain should renew the Trident system, while 22 per cent said it should be scrapped and 10 per cent said the submarines should be used without nuclear missiles.
Defence Secretary Michael Fallon said earlier Monday Britain must keep nuclear weapons to "deter any kind of adversary, whether it's a country or a terrorist group."
"We can't be sure what threats will come against Britain in the 2040s and 2050s," Fallon told BBC Radio 4's Today programme, adding that not renewing the Trident system was "a gamble we simply can't afford to take."
"We need to be sure that [potential attackers] are always unsure as to how we might respond and if we might retaliate," he told the broadcaster.
The missiles are carried on four submarines based in Scotland. But in a recent policy statement, the SNP said nuclear weapons were "immoral, ineffective and expensive."
"In times of imposed austerity, the 205 billion pounds which would be spent on a Trident replacement over the next 30 years could be far, far more effectively used on improving healthcare, childcare, education and building a better future for our children," it said.