The future of a military aircraft project employing 1,000 people in Bristol would be in doubt until at least the end of next year under a Tory government, the Shadow Defence Secretary has admitted.

In an interview with the Bristol Evening Post ahead of his speech to Conservatives activists in Manchester today, Liam Fox said projects could not be propped up simply because they are major local employers.

Instead the Woodspring MP revealed that every major military procurement programme would be re-evaluated under an incoming Conservative government – a measure that would take up to 12 months to complete.

The A400M's 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 Rolls-Royce staff are employed to work on the engines.

Dr Fox told the Evening Post: "You can't just pluck programmes out of the air and say that programme is good, that one's bad, this will be funded, that one won't.

"You have to maintain the discipline of a proper defence review. That will take us between six and 12 months to carry out in office. Only once you have decided what it is you are trying to achieve can you decided which programmes fit that.

"Simply choosing a programme and saying you could save x amount of money by cutting it is like trying to lose weight by cutting out your liver on the basis of what it weighs, not what it does.

"It is very tempting in constituencies across the country to say a certain programme is a big employer here so we'll say we'll keep it. We must maintain the discipline of looking at all the programmes simultaneously."

The project has been besieged by technical problems and is four years behind schedule. The Liberal Democrats are committed to scrapping it but a number of Labour and Conservative backbenchers have also called for the plug to be pulled on the scheme.

Dr Fox said all major procurement projects would be assessed on five tests – capability, affordability, adaptability, interoperability and exportability.

The latter will form a key plank of Tory defence policy, he said, as selling overseas is key to protecting British defence industry jobs.

During his conference speech today he was due to say the changes represent a radical new approach to the way procurement is carried out. The Tories would bring in legislation that would commit governments to holding a strategic defence review every four to five years.

"We are going to have a strategic defence review, we are going to have a shake-up of the Ministry of Defence and we are going to have an overhaul of the procurement process," he said.