Defence Secretary Philip Hammond has announced a U-turn over Britain's new fighter jets for the Royal Navy's new aircraft carriers because of "unacceptable cost growth and project delays".
Mr Hammond said ministers were reverting to plans by the former Labour government to acquire the jump-jet version of the US-built F-35 Joint Strike Fighter, of which there are three versions.
Britain had been looking at two for its carriers - the F-35B jump-jet version and the F-35C catapult-launched version.
While both can operate from aircraft carriers, the catapult-launched version had been the coalition's favourite as it has a greater range and can carry more munitions.
The B version carries about a third less fuel to make room for its vertical flight system.
The C type has been chosen by the US Navy and the French navy, which means the UK's F-35s should have been inter-operable with its allies.
But ministers have now opted for the F-35B jump-jet variant.
The cost of fitting the necessary catapults and arrester gear - "cats and traps" - to one of the Royal Navy's aircraft carriers is reported to have spiralled, making the C variant too expensive.
Mr Hammond told the Commons the costs of fitting the "cats and traps" had more than doubled to £2bn since the time of the Strategic Defence Security Review , adding that the Government would "not blindly pursue projects and ignore cost growth and delays".
He said delays to the F-35C programme meant they would have not been operational until 2023 - three years later than planned.
Mr Hammond told MPs: "Carrier strike with 'cats and traps' using the carrier variant jet no longer represents the best way of delivering carrier strike and I am not prepared to tolerate a three-year further delay to reintroducing our carrier strike capability.
"This announcement means we remain on course to deliver carrier strike in 2020 as a key part of our Future Force 2020."
The decision is an embarrassment for David Cameron , who strongly criticised the original decision by Labour to choose the short take-off and vertical landing jump-jet.
Shadow defence secretary Jim Murphy said the Government's "chaotic" handling of its carrier policy totally undermined its credibility on defence.
"This is a personal humiliation for David Cameron who will to return to Labour's policy, which he previously condemned," he said.
"This is a strategically vital element of the equipment programme on which our security and thousands of jobs depend.
"Yet ministers have treated it with hubristic incompetence, wasting hundreds of millions at a time of painful defence cuts."
Sky News' security and defence editor Sam Kiley said: "Essentially what has happened is that this has been a U-turn on a Government U-turn."
He added: "To be fair to the Government, two years ago the jump-jet version was looking as though it might not even work but recent tests, particularly of the version being sold to the British, are now going very well, so the decision has been taken to basically shelve the bad decision and go back to what might actually work.
"The good news for the Royal Navy is the jump-jet version means that the two new aircraft carriers can come into service."
While the US will be the primary operator of the F-35, The Netherlands, Canada, Turkey, Australia, Norway and Denmark will also be flying the warplane.
The Joint Strike Fighter will be known as the Joint Combat Aircraft in British service, with the US designation F-35 becoming F35.
