Prime Minister Theresa May said she wasn't going to gamble on Britain's safety, as she opened a commons debate on whether to renew Britain's nuclear deterrent.
The Government is committed to replacing the country's ageing fleet of submarines, a motion which Jeremy Corbyn has been vocally against.
Divisions in the Labour party were once again laid bare, as many of Mr Corbyn's own MPs stood up to disagree with him.
Our Political Correspondent Carl Dinnen reports:
Another Scottish independence referendum is fast approaching, SNP warns, after Westminster voted to renew Trident.
Labour MPs reacted angrily after Jeremy Corbyn referred to the party's policy on the UK's nuclear deterrent in the past tense.
Nicola Sturgeon has accused the UK Government of "playing games" over Trident, ahead of MPs voting on the renewal of the nuclear deterrent.