On behalf of 20,000 engineers, managers and specialists working in defence sector, Prospect Assistant General Secretary Mike Clancy welcomed the carrier decision: "This is great news as it supports the long-term sustainability of the UK’s naval dockyards.

"It also has implications for the Naval Base Review, as all the indications are that the aircraft carriers will be based at Portsmouth Naval Base, thereby securing the future of thousands of jobs that were hanging in the balance.

"The announcement is particularly significant as it marks the beginning of a new collaboration between the public and private sector defence contractors which is at the heart of the government’s vision for the future of the MOD, as outlined in the Defence industrial Strategy. Our members in the alliance of companies engaged on the carriers – BAE Systems, VT and Babcock – are looking forward to working in partnership with their MOD colleagues."

However, Prospect National Secretary Steve Jary, responding to the accompanying announcement of a 1.5% per annum increase in the defence budget, said: " Prospect has warned that this will not be sufficient to pay for the new carriers, Trident’s replacement and the high level of operational commitment faced by our armed forces.

"Other parts of the defence effort will suffer as a result of this announcement, leading to cuts in support functions. The MOD is planning further drastic reductions in civilian numbers and this can only damage the effectiveness of our armed forces."