Lib Dem leader calls for UK-built nuclear missiles

Liberal Democrat leader Sir Ed Davey has called on the UK government to begin developing a domestically built nuclear missile system, arguing Britain should no longer depend on the United States for a key component of its nuclear deterrent.

Writing on the party’s website, Davey said the UK should work towards what he described as a “fully independent British nuclear deterrent”, ending reliance on the US-supplied Trident missile system carried by Royal Navy submarines.

Britain’s nuclear deterrent is based on four Vanguard-class ballistic missile submarines, each capable of carrying Trident II D5 missiles armed with UK-designed nuclear warheads. While the warheads and launch decisions are fully controlled by the UK, the missiles themselves are drawn from a shared US-maintained pool.

Davey argued that reliance on American systems could create risks for the UK’s long-term strategic autonomy. “If the answer to ‘Is our nuclear deterrent working?’ depends on what Donald Trump had for breakfast, then the answer is no, it’s not. And our deterrent is not truly independent. This should be keeping British defence planners awake at night.”

He said Britain’s current system meant a key element of the deterrent relied on US support. “The Trident missiles sitting in our Vanguard submarines are leased from the United States. Their maintenance depends on American facilities. That means the operability of our deterrent ultimately depends on the goodwill of whoever sits in the Oval Office.”

Davey argued the UK should begin developing a sovereign missile capability ahead of the expected retirement of the current Trident system in the 2040s. “Trident missiles will need replacing in 2042. If we haven’t built our own capability before then, we’ll have no choice but to go back to the Americans. Who knows what terms they’ll offer? We cannot afford to leave our national security to chance.”

He said Britain had previously demonstrated the ability to develop nuclear weapons technology independently and should be capable of doing so again.

“I know building a sovereign capability sounds like an enormous undertaking. It is. It will cost billions over the next two decades. But Britain can do it – because we’ve done it before. If France can maintain a fully independent deterrent, Britain certainly can.”

The UK’s nuclear deterrent is often described as “operationally independent”, meaning the decision to launch nuclear weapons rests solely with the British government and Prime Minister. Once a submarine is on patrol, it can operate autonomously and does not require external permission or control to launch its missiles.

However, the system relies on cooperation with the United States for missile supply, maintenance and elements of supporting infrastructure. Davey said Britain should initially focus on developing the ability to maintain existing Trident missiles domestically before moving towards designing and producing a replacement missile system.

“In the short term, that means developing our own capability to maintain existing Trident missiles here in the UK. In the longer term, when those missiles come to the end of their lives, we will have British-made replacements ready. But only if the government starts that work now.”