Defence Secretary Philip Hammond is to make a Commons statement on the defence equipment programme amid reports of a major U-turn on the Royal Navy's aircraft carriers, Downing Street said today.
The Prime Minister's official spokesman said Mr Hammond was expected to address MPs before Easter following reports of a rethink over the carriers' Joint Strike Fighter aircraft.
Ministers are said to be considering whether to revert to the original plan by the former Labour government to acquire the F-35B "jump jet" variant of the aircraft.
That proposal was dropped in the 2010 Strategic Defence and Security Review which opted instead to switch to the F-35C carrier version, which has a longer range, can carry more weapons and is interoperable with the French and US navies.
In their foreword to the SDSR David Cameron and Nick Clegg described the original Labour decision as an "error" which they were determined to rectify.
However, it is reported the costs of fitting one of the two carriers with the necessary catapults and arrester wires - "cats and traps" - has sky-rocketed by up to £2 billion, and it will not be ready until 2027 - seven years later than currently planned.
The Prime Minister's spokesman said today that managing the defence equipment programme was an "ongoing process" and that an announcement was expected "soon". He confirmed that Mr Cameron was taking a close interest in the issue.
"He took a very strong interest in the process leading up the SDSR," he said.
"Because of the problems we have had in the department in the past, it is an ongoing process to try to manage the equipment programme better."
A MoD spokesman said they were currently finalising the budget for 2012-13 and "balancing" the equipment plan.
"This means reviewing all programmes, including elements of the carrier strike programme, to validate costs and ensure risks are properly managed. The Defence Secretary expects to announce the outcome of this process to Parliament before Easter," a spokesman said.
"The intention to move to a 'cats and traps' based carrier strike capability was always subject to a detailed piece of work to assess the costs and risks involved in converting a Queen Elizabeth class carrier. That work is ongoing."