A NUCLEAR deterrent onboard submarines due to be built in Barrow has never been needed more than in today's less predictable, more dangerous world, Defence Secretary Michael Fallon has said.

Michael Fallon Mr Fallon underlined the case for renewing the UK's Trident weapons system on a visit to the Faslane naval base on the Clyde, where he received a tour of HMS Vigilant, one of the UK's four nuclear warhead-carrying submarines.

He said he hoped a parliamentary vote endorsing the government's planned renewal programme will take place "shortly".

Mr Fallon said: "We have not fixed a date yet but we need to do it, certainly this year, because we need to get on and replace these four boats to ensure the nuclear deterrent can still be provided throughout the 2030s, 40s and 50s."

How much will the renewal Trident cost?

The Ministry of Defence estimates that acquiring four new submarines to carry the Trident deterrent will cost £31 billion over the course of the 20-year procurement programme, with a further £10 billion set aside to meet any additional unexpected cost increases.

Hasn't work already started on the submarines?

Mr Fallon said: "We're already starting to order some of the items that Parliament authorised expenditure for at the end of the last parliament, so we're preparing the design of the boats but it takes 10 to 12 years to build a new nuclear submarine and test it properly.

"We need to get on with it now, in this parliament, so that the boats are ready to replace these Vanguard boats from the beginning of the 2030s."