Declassified documents from the British National Archives have confirmed what was largely an unofficial rumour.

The declassified documents from the British National Archives show that former US President Ronald Reagan had offered British Prime Minister Margaret Thatcher a chance for both countries to work on the F-117 stealth fighter programme back in 1986.

The programme was given the code-name Project Moonflower. It is understood that the British Ministry of Defence declined the offer as it was still a ‘black programme’.

The later version offered to the Royal Air Force in 1995 was the F-117C. The aircraft was to be a baseline F-117A fitted with British avionics and EJ200 engines, plus a number of BAE structural components or sub-assemblies.

The F-117 was based on the Have Blue technology demonstrator and was the first operational aircraft to be designed around stealth technology. The maiden flight of the Nighthawk took place in 1981 and the aircraft achieved initial operating capability status in 1983.

The Nighthawk was shrouded in secrecy until it was revealed to the public in 1988.