UK to build up to 12 new attack submarines

2 June 2025

Paul Seddon

Political reporter

Jonathan Beale

Defence correspondent•@bealejonathan

PA Media

An illustration of what an SSN-AUKUS submarine will look like

The UK will build "up to" 12 new attack submarines, the prime minister has announced, as the government unveils its major defence review on Monday.

The new conventionally-armed, nuclear-powered submarines will replace the seven-strong Astute class from the late 2030s onwards.

The review is expected to recommend the armed forces move to "warfighting readiness" to deter growing threats faced by the UK.

Sir Keir Starmer said the government will adopt a "Nato-first" stance towards defence, so that everything it does adds to the strength of the alliance.

The threat posed by Moscow has been a key part of the government's pitch ahead of Monday's review, led by ex-Labour defence secretary Lord Robertson, which was commissioned by Labour shortly after it took office last July.

The report will make 62 recommendations, which the government is expected to accept in full.

Speaking to BBC Radio 4's Today programme ahead of its publication, Sir Keir said the danger posed by Russia "cannot be ignored" and the "best way" to deter conflict was to prepare for it.