The UK will build "up to" 12 new attack submarines, the prime minister will announce, 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.

Amid rising global tensions, Prime Minister Keir Starmer outlined rearmament plans aimed at deterring an increasingly hostile Russia.

The UK intends to send a “message to Moscow” with plans to expand its fleet of attack submarines and invest in its nuclear deterrent as part of a new defense strategy to head off the threat posed by Russia.