Image copyright Lockheed Martin

The first UK appearance of the combat jet due to be used on Britain's new aircraft carriers has been cancelled.

It was hoped the F-35B Lightning IIs would be at the Royal International Air Tattoo in Fairford, Gloucestershire which, starts on Friday.

But last week the entire fleet of F-35's was grounded in the US following an engine fire.

There is still some optimism that the jet might appear at the Farnborough Air Show which starts on Monday.

Organisers of the tattoo said in a statement: "Despite everyone's best endeavours, it has now been decided that the Lockheed Martin F-35B Lightning II will not fly at the Royal International Air Tattoo (RIAT) 2014 as all of the aircraft currently remain grounded."

At a cost of around $400bn (£230bn), the F-35 family of jets is the most expensive defence project in US history.

Image copyright Lockheed Martin

Britain has invested heavily in the jet and some 500 British companies are involved in the project.

The initial UK order for 14 F-35Bs will, with support costs added, have a price tag of about £2.5bn.

BAE Systems has invested £150m in facilities that will build the rear part of the fuselage and tail fins.

BAE says it employs 2,000 "highly skilled" staff on the programme in the UK.

But the project, led by US-based Lockheed Martin, has been hit by repeated delays and cost overruns.

'Quite embarrassing'

Last week the US Air Force and the US Navy grounded the aircraft following an engine fire on one of the planes.

That has jeopardised the plane's appearance at the Farnborough Air Show, where four of the F-35B models - also known as the Lightning II's - were due to appear.

"If the F-35 doesn't make it to the show it's quite embarrassing. It will jeopardise the timing of export orders," said Richard Aboulafia, an analyst with Teal Group.

"But assuming there's no major problems here, we aren't expecting a serious blow to the programme."

Last week the Queen named one of the aircraft carriers due to carry the jets.

The RAF is taking the lead on bringing the jets into service, although each squadron of F-35B Lightning IIs will be joint with the Fleet Air Arm, with the first flight trials on board HMS Queen Elizabeth due in 2018.