Britain’s nuclear submarine fleet ‘no longer fit for purpose’.

The admiral, who led the Trident value for money review in 2010, called for Britain to pull out of the multi-billion “Aukus” defence deal with America and Australia to build 12 new nuclear submarines.

SSN-Aukus is a submarine which is not going to deliver what the UK or Australia needs in terms of capability or timescale. “Performance across all aspects of the
programme continues to get worse in every dimension.”

Former Navy chief calls for ‘radical’ action to revive programme after catastrophic failures.

Tom Cotterill, Defence Editor, 06 December 2025

Britain is “no longer capable” of running a nuclear submarine programme after “catastrophic” failures pushed it to the brink, a former Navy chief has warned. In an extraordinary critique, Rear Admiral Philip Mathias said the UK’s “silent service” was facing an “unprecedented” situation that it was “highly unlikely” to recover from without a “radical” intervention. The former director of nuclear policy at the Ministry of Defence (MoD) said delays in building new attack boats had reached record levels and had driven up the duration of patrols for crews from 70 days during the Cold War to more than 200 now.

This had led to the “shockingly low availability” of submarines to “counter the Russian threat in the North Atlantic”, the retired submarine commander warned. The admiral, who led the Trident value for money review in 2010, called for Britain to pull out of the multi-billion “Aukus” defence deal with America and Australia to build 12 new nuclear submarines.

“The UK is no longer capable of managing a nuclear submarine
programme,” he said. “Dreadnought is late, Astute class submarine delivery is getting later, there is a massive backlog in Astute class maintenance and refitting, which continues to get worse, and SSN-Aukus is a submarine which is not going to deliver what the UK or Australia needs in terms of capability or timescale. “Performance across all aspects of the
programme continues to get worse in every dimension.”

He added: “This is an unprecedented situation in the nuclear submarine age. It is a catastrophic failure of succession and leadership planning.” The Navy’s fleet of Astute submarines is already facing significant problems, with many having been stuck in port for years. Out of the seven planned, only
six are in service.

He also criticised the role of industry giants for
delays to programmes. He added not a single of the UK’s 23 decommissioned nuclear boats had been dismantled since the first, HMS Dreadnought, left service in 1980. “This is an utter disgrace and brings into question whether Britain is responsible enough to own nuclear submarines,” the admiral said.

Telegraph 6th Dec 2025,
https://www.telegraph.co.uk/news/2025/12/06/britains-nuclear-submarine-fleet-no-longer-fit-for-purpose/