Media playback is unsupported on your device Media caption Defence Secretary Liam Fox: "Sharing an aircraft carrier is utterly unrealistic"

Defence Secretary Liam Fox has ruled out the UK sharing aircraft carriers with France as part of closer defence co-operation and efforts to save money.

Dr Fox, who is in Paris for talks with his French counterpart, said such a move would be "utterly unrealistic".

The Ministry of Defence, like nearly all government departments, is facing a significant cut in its future budget.

Dr Fox wants to save money in procurement and administration while prioritising front-line operations.

He has emphasised the need for much closer working with key European allies, such as France.

But at a press conference with French Defence Minister Herve Morin, Dr Fox dismissed suggestions the two could share aircraft carriers as a cost-saving measure.

The UK and France are facing the realities of the tough financial climate and it is in our best interests to work together to deliver the capabilities that both our nations need Liam Fox, Defence Secretary

"In terms of actually being able to share an aircraft carrier, I would have thought that was utterly unrealistic," he said.

However, the two men said they would look at ways of sharing their respective fleets of A400M, a plane designed to transport soldiers and heavy equipment to combat zones.

'Tough climate'

All British government departments, except international aid and health, are facing budget cuts of between 25% and 40%. Defence, although unlikely to be among the hardest hit, will not be immune.

This has led to speculation that plans for two new aircraft carriers by 2018 - costing £5bn - could be scaled back.

Dr Fox said the future shape of the aircraft carrier fleet would be decided as part of a strategic defence review - due to be concluded later this year.

"You have to wait to see what assets you have before you can consider the pulling them," he said.

Closer co-operation with France on defence was in the UK's interest, Dr Fox added.

"The UK and France are facing the realities of the tough financial climate and it is in our best interests to work together to deliver the capabilities that both our nations need."

Trident costs

As the UK's future military capability is assessed, ministers have said the mission in Afghanistan will remain a priority but Dr Fox has declined to rule out cuts in overall troop numbers across the armed forces.

The Treasury has also insisted that the MoD must foot the bill for renewal of the Trident nuclear weapon system, subject of a separate value-for-money review. This would put further pressure on the MoD's budget.

While welcoming the dialogue with the French government, former security minister Lord West told BBC Radio 5 live that there was a limit to what military resources countries can share.

"Do we really want the French using a British carrier if it's to do with one of their dependencies abroad and some incident comes up and there's fighting there?" he said.

"Do you want to find British pilots bombing people for a French reason?"