Britain’s nuclear deterrent would be at risk from Chinese interference if the Prime Minister capitulates over the Chagos Islands, senior defence sources warn.
A top-secret satellite system used to direct British and US nuclear missiles would be compromised if Keir Starmer signs off a deal with China-friendly Mauritius, they fear.
The UK is locked in negotiations, led by Attorney General Lord Hermer and National Security Adviser Jonathan Powell, over handing over the strategically important islands in the Indian Ocean following a UN ruling.
The archipelago, controlled by the UK for more than two centuries, is home to the joint UK-US Diego Garcia military base. Britain is set to pay billions to Mauritius to lease the base back for 99 years under the terms of the deal.
But senior defence sources warn that the UK’s system for co-ordinating nuclear missiles relies on connection points on the Diego Garcia base.
To function properly, these ‘nodes’ require physical protection and British control of the island’s electromagnetic spectrum.
But the deal includes a clause saying other countries could also use the spectrum, from which Mauritius could profit.
According to senior sources, this could offer Beijing a gateway to jamming the top-secret Automated Digital Network System 3 (ADNS 3), which is shared by the Royal Navy and the US Navy and, crucially, is part of the ‘Nuclear Firing Chain’ (NFC).
Downing Street told reporters that the deal would enhance UK national security, insisting that without it, Britain would lose access to the spectrum.
‘The very clear advice that we have is that the future operation of the base without a deal would be at risk,’ a spokesman said.
But Conservative former defence secretary Ben Wallace said: ‘This is a totally fabricated excuse by the Cabinet Office.
‘The islands are far more important than just this and the potential threat to our operations [from no deal] is a total fiction from the pen of the Cabinet Office comms and no doubt [human rights law firm] Leigh Day’s best mate Lord Hermer.’
Lord Hermer was a go-to barrister for Leigh Day before his appointment as Attorney
General last year and he has been accused of a deference to international law over domestic needs.
Leigh Day is currently representing asylum seekers who claim they were trapped on the Chagos Islands after being rescued at sea by the Royal Navy.
In 2019, the International Court of Justice ruled that Britain’s continued administration of the islands was unlawful.
Despite the UK ignoring the ruling, it was subsequently ratified by the UN General Assembly, which found the islands rightfully belonged to Mauritius.
Sir Ben added: ‘Many of the UN judges who made the flawed ruling come from totalitarian states including China.
‘Is the PM really going to put their opinions before that of Britain’s security? Diego Garcia is British and must remain so.’
MP Tom Tugendhat wrote on X that in his former role of security minister, he had seen the advice on the implications of the deal and the version being presented to the public was ‘nonsense’.
The settlement could also mean that the Royal Navy could be prevented from entering a buffer zone which Mauritius intends to set up around the islands.
Without any protection from Western navies, sources fear that China could get close enough to the sensitive military facilities.
A source said: ‘ADNS 3 provides assured tactical wide area networking between ships and shore around the world to support full battlespace connectivity.
‘Britain’s nuclear threat is carried by the Royal Navy’s bomber submarines. We cannot risk any breakdown of communications or hostile interception of messages which are part of the NFC.
‘If there was a breach, Britain would lose its nuclear deterrent.
‘This is a highly technical matter, involving a lot of classified systems, which is seemingly being overlooked by ‘Leftie’ government lawyers.
‘This part of the world is a key part of China’s expansionist agenda, which the UK appears to want to facilitate. These systems rely on guarantees around the security of Diego Garcia.’