The White House could "switch off the UK's nuclear deterrent" as fears of an impending military confrontation with Russia continue to grow, a leading academic has warned. The UK's Trident nuclear defence system is operationally independent, meaning the Prime Minister can order a strike without relying on another party.

However, the nuclear technology built into the Trident missiles is leased from US company Lockheed Martin, and without a suitable alternative the UK is entirely reliant on American maintenance to keep the deterrence operational, Dr. Becky Alexis-Martin warned. "The submarine, and the rest of the UK’s nuclear fleet, is heavily reliant on the US as an operating partner. And at a time when the US becomes an increasingly unreliable partner under the leadership of an entirely transactional president, this is not ideal. The US can, if it chooses, effectively switch off the UK’s nuclear deterrent", the University of Bradford nuclear weapons academic wrote in The Conversation.

The alarming warning comes after the Prime Minister laid the keel of the "next generation" of UK nuclear missile-carrying submarines in Barrow-in-Furness last week. The Dreadnought class of nuclear submarines will replace the Vanguard class currently in operation.

The new class of submarines will offer increased stealthiness, according to the Ministry of Defence (MoD), with improved rudder technology.

Defence Secretary John Healey said of the transition from Dreadnought to Vanguard: "Today’s keel laying is a demonstration of our Government delivering for defence and fulfilling our first duty: to keep the British people safe.

"Our triple lock pledge for Britain’s nuclear deterrent will see all four Dreadnought-class submarines built in Royal Barrow – a generational commitment that is transforming this town. This is one of the most complex projects ever undertaken in this country, representing the very best of British engineering.

"Our commitment to the nuclear deterrent is unshakeable – it is the ultimate guarantor of our national security and the security of our NATO allies. And this national endeavour is also an engine for jobs and growth in Barrow and beyond."

However, the new submarines will still be armed with Lockheed Martin's Trident missiles, meaning the UK will still require US collaboration for maintenance and support.

Dr Alexis-Martin warned that if the US did back away from assisting the MoD, the UK would have few viable options to ensure a continuous nuclear deterrence.

"If the US were to renege on its commitments, the UK would either have to produce its own weapons domestically, collaborate with France or Europe or disarm", she said.

"Each scenario creates new issues for the UK. Manufacturing nuclear weapons from scratch in the UK, for example, would be a costly and protracted activity".