Committee questions whether attack submarines put to sea

Evidence of low availability among destroyers, frigates and attack submarines raises serious questions about whether Britain can meet its High North commitments before new capabilities enter service, according to a report by the Defence Committee.

The committee, chaired by Tan Dhesi, the Labour member for Slough, records reporting that all five of the Astute class nuclear attack submarines then in service had recently been tied up in dockyards at the same time, with none deployed.

Dhesi said: “The UK needs to be willing to address a hard truth: it does not currently have all the capabilities to operate successfully in the High North. Russian submarine and sabotage forces in the High North pose direct risks to the North Atlantic and the UK, including the nuclear deterrent. Despite this, the Ministry of Defence has accepted a serious anti-submarine warfare gap. Publicly available evidence of low availability among destroyers, frigates and attack submarines calls into question whether the UK can meet its commitments in the High North.”

Professor David Blagden of the University of Exeter told the committee: “[i]t was reported in the media quite recently that a French SSN [attack submarine] had been seen in Faslane around the time that one of [our] SSBNs sailed on its patrol… [i]s this the French now doing ‘delousing’ for a UK nuclear deterrent submarine going on patrol? Is that great alliance solidarity or is it, ‘Oh my god, we can’t get one of our own SSNs to sea to do one of the highest missions?'”

Delousing is the activity in which an attack submarine sanitises the waters around a ballistic missile submarine to ensure it is not being tracked or tailed by an adversary as it leaves on or returns from a deterrent patrol.

The Rt Hon the Lord Case, chair of Team Barrow, told the committee in November 2025 that the government is saying to the defence industry “[p]lease, how quickly can you build our nuclear submarines for us? We are having to make up for decades of neglect.”

Retired Rear Admiral Philip Mathias, a former Director of Nuclear Policy at the Ministry of Defence, said in December 2025 that one consequence of a lack of investment in the submarine fleet was that the duration of patrols for Vanguard class crews, which were seventy days during the Cold War, were now more than two hundred days, and that there was a shockingly low availability of submarines to counter the Russian threat in the High North.

The committee’s conclusion states: “The Royal Marines’ Arctic expertise is a significant national strength, but it cannot compensate for shortfalls in the naval platforms needed to deploy, protect and sustain operations in the region. The UK’s ability to deter and respond to threats in the High North depends not only on future programmes, but also on the readiness of the Royal Navy’s existing ships, submarines and specialist forces. Russian submarine and seabed warfare capabilities based in the High North pose direct risks to the North Atlantic, UK waters and the nuclear deterrent. Evidence of low availability among destroyers, frigates and attack submarines therefore raises serious questions about whether the UK can meet its High North commitments before new capabilities enter service.”

The committee asks the government to provide a plan setting out how the department will improve the availability of the Royal Navy’s frigates, destroyers and attack submarines before 2030, noting that the update might be presented at a classified level but that it expects a version to be made publicly available.

Ministers have consistently declined to disclose submarine availability, and Luke Pollard MP told Parliament this week that it is British policy not to disclose the operational availability or deployment details of submarines, as doing so would be likely to prejudice the capability, effectiveness or security of the armed forces.