LONDON - Prime Minister David Cameron's Conservative Party on Thursday promised to renew the country's ageing nuclear submarine fleet if it wins a May 7 national election, hoping to put pressure on their main rivals Labour to match the commitment.
Replacing the vessels carrying the Trident missiles - four Vanguard-class submarines - is expected to cost 20 billion pounds (S$40.5 billion) with a final decision on the renewal due to be taken in 2016.
Opponents argue replacing Trident could cost as much as 100 billion pounds and Britain should consider cheaper alternatives.
"The Conservative manifesto will guarantee that we will build a new fleet of four Successor ballistic missile submarines," Defence Secretary Michael Fallon wrote in the Times newspaper.
"We will retain the Trident continuous-at-sea nuclear deterrent to provide the ultimate guarantee of our safety."
The Conservatives have long supported renewing Trident, and Thursday's pledge is designed as a challenge to Labour which, whilst also backing the programme, has mooted the idea that three submarines could fulfil the same role.
With neither Labour or the Conservatives forecast to win the election outright, Labour's most likely route to power is a deal with the Scottish National Party (SNP) who vocally oppose any renewal of the fleet, which is based in Scotland.
SNP leader Nicola Sturgeon on Wednesday said her party would"never ever, ever" vote for a renewal of the Trident programme, potentially complicating post-election government-forming negotiations.
"Labour is committed to maintaining a minimum, credible, independent nuclear deterrent, delivered through a continuous-at-sea deterrent," Labour defence spokesman Vernon Coaker said in a statement.
"This is not up for negotiation with any party."