UK-based think tank 878 Institute has recommended that two of the UK Royal Navy's five in-service Astute-class nuclear-powered attack submarines (SSNs) remain fully deployable at all times.
One SSN would patrol the approaches to the UK and the other would support the country's Continuous At-Sea Deterrent (CASD), the institute suggested.
The recommendations appear in the institute's October briefing, The Condition of the Royal Navy and the Threat to Britain — Briefing 1. The Submarine Fleet. They are not announced Royal Navy policy.
The institute called for, "one actively patrolling the North Sea, the Greenland-Iceland-UK Gap, or English Channel to deter increased Russian submarine activity around British waters; a second always patrolling alongside the CASD."
It linked that requirement to more resources for the class. It noted that all five boats, "were in docks for a period from June 2026," and cited, "maintenance backlogs, industrial bottlenecks, and dockyard infrastructure limitations."
"Without this, the Astute-class must be said to be failing, and with it, Britain's nuclear deterrent risks being left defenceless at sea or dependent upon allies for support," the briefing stated.
The institute also urged the government to commit to 12 SSN-AUKUS submarines, likely at the spring 2027 Spending Review. It also recommended that the UK Ministry of Defence (MOD) commission early definition work on a successor to the Dreadnought-class ballistic missile submarines by the end of 2027.
The government's September 25 announcement retained the wording "up to 12" SSN-AUKUS boats. The MOD expects to decide the total before the detailed design and long lead phase ends in 2028.
In an October 20 written parliamentary answer, the MOD declined to say how many Astute-class boats were operational, adding that, "it is UK policy not to disclose the operational availability or deployment details of submarines."
