Mike Clancy, Prospect Assistant General Secretary, said the news would come as a huge relief to thousands of workers in defence. “After months of delay, this decision will secure the jobs of 20,000 defence professionals in the public and private sectors.

“It will be particularly welcome for workers in BAE Systems, Vickers, Vosper Thornycroft and Babcock who were facing the prospect of major job losses if the order was cancelled.”

Clancy said the aircraft carrier decision was an important reassurance that the cornerstone of the Defence Industrial Strategy remains in place, which would guarantee the jobs of British workers in defence. But he stressed that other vital defence projects should not be starved of funds to enable the construction of the aircraft carriers.