Mr Brown says there are no plans to merge the British and French navies
Gordon Brown has rejected suggestions that the French and British navies could merge as "totally untrue".
Speaking at prime minister's questions, he dismissed reports that HMS Ark Royal or HMS Illustrious could be controlled from Brussels.
He told MPs: "There is no proposal to merge the use of aircraft carriers."
The Sun reported that French President Nicolas Sarkozy had opened talks with Mr Brown about plans to put a British aircraft carrier in an EU Navy.
The report suggested it would be "flying the European flag" and be "directed by Brussels".
During his weekly questioning in the Commons, Mr Brown welcomed France's decision to rejoin the military command of Nato following a major defence review, and said he hoped co-operation within Nato could be enhanced.
But he added: "I have to say it is totally untrue that we are trying to merge the British and French navies - and that is not something we will do."
The French have said beefing up the EU's military capability will be a key part of their six-month presidency.
But Eurosceptic Labour MP Ian Davidson asked whether the "collapse" of the EU Treaty would mean an end to EU defence arrangements being put forward.
Mr Brown replied that all co-operation had been announced during President Sarkozy's visit to Britain a few months ago.
"I repeat, there is no proposal to merge the use of aircraft carrier as has been suggested in the press.
"If one looks at the French statement .. it does not say that. It says there will be association - in other words we will work together, not merge, not amalgamate."