Audacious is the fourth of the seven Astute Class submarines being built for the Royal Navy.

BBC: HMS Audacious: MoD announces ?1.2bn submarine contract

On paper, at least, the Astute class is a significant step forward.

BBC: HMS Astute recovers from shaky start

The ongoing revamp is timed to coincide with the arrival in 2009 of the new Astute class of hunter killer submarines, currently being built at Barrow-in-Furness in Cumbria.

BBC: NEWS | UK | Scotland | Glasgow and West | Sailors move in to ?125m quarters

Since the reactors would be able to power both the Astute class attack submarines and the replacement for the Trident missile-armed Vanguard class, the announcement had "nothing to do with weapons", Mr Hammond told MPs.

BBC: Urgent question: Nuclear-powered submarines

William and Catherine, who are known as the Earl and Countess of Strathearn in Scotland, were due to travel to Barrow-in-Furness, Cumbria, to learn about the new Astute Class of nuclear powered submarines being built for the Royal Navy by BAE Systems.

BBC: Outdoor centre opening

Further write-offs loom over two contracts, for Nimrod marine-surveillance aircraft and new Astute-class nuclear submarines.

ECONOMIST: Britain's defence champion is under fire