Two-thirds of the cabinet in Margaret Thatcher's Conservative government opposed her decision to buy the Trident nuclear deterrent, according to official documents made public.
In 1980, Mrs Thatcher struck a deal with US President Jimmy Carter for Britain to buy the Trident submarine-launched missile system to Britain to replace the UK's ageing Polaris deterrent.
The following year, however, she was forced unexpectedly to reopen the agreement after Mr Carter's successor, Ronald Reagan, opted for the more expensive Trident II variant - leaving Britain to either follow suit or be left with an out-dated system.
Files released by the National Archives show defence secretary John Nott warned Mrs Thatcher that they would have to "deal with all the issues" surrounding the acquisition in the teeth of strong opposition from within the Tory ranks.
"It was essential to do so since two-thirds of the party and two-thirds of the Cabinet were opposed to the procurement of Trident," Mr Nott told her. "Even the chiefs of staff were not unanimous."
Although Mr Nott warned that the cost of the programme looked set to double - from £5 billion to £10 billion - he decision to press ahead received strong backing from the foreign secretary, Lord Carrington.
If Britain did not get Trident, France would be left as the only nuclear power in Europe. "This would be intolerable," he said.
However Mr Nott's concerns were echoed by trade secretary John Biffen who said the decision to go ahead with Trident could be seen as cutting the resources available for conventional forces at time when the military was already over-stretched.
"In such circumstances anti-nuclear sentiment will go much wider than in the 1950s and, in the circumstances, could be electorally harmful," he said.
Such views may have accounted for Mrs Thatcher's decision to avoid a full Cabinet discussion before the original decision to acquire Trident was announced by Mr Nott's predecessor, Francis Pym, in July 1980.
A note from the cabinet secretary Sir Robin Armstrong explained a cabinet discussion had be planned until a last-minute warning from the White House that The New York Times was about to break the story, including details of Mrs Thatcher's correspondence with Mr Carter.
"After consulting a few colleagues (who took the view that bringing forward the announcement by 48 hours would be the best way out of a difficult situation) you agreed that the timetable should be advanced by 48 hours," he wrote.
Sir Robin acknowledged nothing had actually appeared in the newspaper, but insisted the reporter concerned was "very angry at having been forestalled" by the decision to bring forward the announcement.
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