North Somerset MP Liam Fox is at the centre of a row over Tory defence cuts that could hit Bristol's A400M contract.

Shadow Chancellor George Osborne has been accused of planning to save £3 billion if the Conservatives win the next General Election by axing Britain's commitment to the troubled military transport aircraft programme.

But shadow defence secretary Mr Fox, who represents the Woodspring constituency, has reportedly emailed firms pledging to save the project – a claim officials deny.

The party insists it has made no decision on the future of the aircraft. Its wings and composite parts are being designed and made by Airbus and GKN at Filton, where about 900 workers are involved in the project.

A further 100 at Rolls-Royce in Patchway are working to make the engines

But last week the Bristol Evening Post told how a series of Tory backbench MPs called for the project to be ditched, claiming it would never be finished.

Armed Forces minister Bob Ainsworth said: "George Osborne is keeping his cuts hidden from the public and the shadow Cabinet, too."

The plane would be capable of carrying military tanks but has been dogged by problems and is four years behind schedule.

The Government has already warned EADS, which is running the £18.5bn contract, it is "concerned" about delays and is considering a new order for rival Boeing's C-17.

Mr Fox insisted no decision had been made and a full review of defence capabilities would be carried out if the party wins at the next election.

He added: "Upon entering office the Conservative Party will conduct a Strategic Defence Review in order to determine the future size, composition and the capabilities required of our Armed Forces and properly to assess the military threats and challenges which face the United Kingdom.

"Under a Conservative Government an SDR will be conducted every four years. The last SDR was conducted in 1998. It is unacceptable that our Armed Forces have to operate on defence planning assumptions designed for the pre 9/11 world."

A spokeswoman for Airbus refused to comment on the Tory row but said: "The A400M is unique, and because it was jointly defined by the major European armed forces, it really responds to their needs."