Foreign Secretary Dominic Raab said it is important to maintain a “minimum credible” nuclear deterrent in response to the Government’s Integrated Review of security, defence, development and foreign policy.

Boris Johnson is to set out the UK's post-Brexit foreign policy, which will involve raising the cap on Britain’s stockpile of Trident nuclear warheads, later today.

It will involve increasing the limit from 180 to 260 warheads, according a leaked copy of the document obtained by the Guardian.

The paper said that it paves the way for a £10 billion rearmament in response to perceived threats from Russia and China.

This will end three decades of gradual disaramament.

HeraldScotland:

When asked whether placing more warheads on the Clyde and the Gare Loch strengthens the Union, Foreign Secretary Dominic Raab said it is important to maintain a “minimum credible” nuclear deterrent.

He told BBC Good Morning Scotland: “I think it’s important that we maintain a minimal credible deterrent against the very worst threats that we face.”

When it was suggested to him that there was "every prospect" of more nuclear warheads, as the cap lifts, Mr Raab replied: “That’s not quite right, it is true and the details of this will be published this afternoon, but the policy is to maintain a minimum credible deterrent, so the question is how many, what level of warheads we need in order to secure that.”

READ MORE: UK Govt foreign and defence review to create two new operation centres to 'tackle threats of the future'

Asked why you would lift the cap if you were not going to increase the number, he added: “The question is what minimum level of credible deterrent you need and the secondary question is what’s the means to that end, how many warheads you’ll need.”

Elsewhere, the review is said to warn there is a “realistic possibility” that a terrorist group will launch a successful chemical, biological, radiological or nuclear (CBRN) attack by 2030.

The Prime Minister will set out the findings of the year-long survey in the Commons later today.

It is expected to include the creation of a new state-of-the-art counter-terrorism operations centre to streamline the response of police and the intelligence agencies in the event of an attack.Gavin Williamson visit to HM Naval Base Clyde

The will also be a new “situation centre” in the Cabinet Office similar to the White House situation room where Barack Obama was able to watch the US special forces operation to kill Osama bin Laden in real time.

The 100-page document – entitled Global Britain in a Competitive Age – argues the increase in nuclear warheads cap is “in recognition of the evolving security environment” and the “developing range of technological and doctrinal threats,” the Guardian said.

The review adds: “A minimum, credible, independent nuclear deterrent, assigned to the defence of Nato, remains essential in order to guarantee our security and that of our allies."