The group (whose UK co-chair is the former Defence and Foreign Secretary Sir Malcolm Rifkind) also argues that removing them from combat bases would greatly increase early warning and decision time, and therefore reduce any remaining concern of a sudden nuclear attack.

BBC: Tactical nuclear weapons 'are an anachronism'

The NAO report also casts doubt on the MoD's claim that the new carrier-based strike force will be fully operational by 2020, saying a decision to delay investment in Crowsnest, a helicopter-based early warning system, means it will be two years late.

BBC: Carrier fighter jet U-turn cost ?74m, says audit office