The Royal Navy and RAF could be forced to draft in personnel from other friendly countries, such as the US, Australia and France, former commanders have claimed.

Up to 4,000 extra staff are needed to run the UK’s two new aircraft carriers and the nuclear submarine fleet, The Daily Mail reported.

Retired Vice Admiral Sir Jeremy Blackham said: “From a naval point of view, there is a serious problem.

“It’s said to be, when I last spoke to the Fleet Commander, of the order of 3,500 to 4,000 people.”

He said “it would be impossible to send ships to sea fully manned” unless the Navy was given more staff.

“There is a serious manpower problem which will negate some of the investment we are making in equipment unless it is addressed,” Sir Jeremy said.

“There is a deal on the table but it falls very, very far short. The Navy has been looking at the possibility of recruiting from other appropriate nations to assist with manning ships.”

The Royal Navy has lost 5,500 personnel since 2010, while the RAF has lost 8,500.