French support for Britain staying in the European Union has slumped, two polls to be published in rival newspapers on Sunday indicate, albeit with some major differences and unexpected caveats.

One of the surveys, carried out for tabloid Le Parisien's Sunday edition, suggests a narrow majority of voters would be happy to see their cross-channel neighbor walk away after the in-out referendum promised by British Prime Minister David Cameron.

Voters polled by the Journal du Dimanche, in contrast, supported Britain staying in by a 58-42 majority.

That headline figure disguised a remarkable discrepancy in the opinions of men and women.

French women, according to the JDD poll, are strongly in favor (69 percent) of Cameron and his compatriots continuing to enjoy the full privileges of membership of the 27-nation bloc.

French men favor saying 'au revoir' to Britain by a 54-46 majority.

[Meanwhile French newspaper] Le Parisien's poll produced an overall 52-48 balance of opinion in favour of Britain leaving the EU amongst those that had a view (97 percent of those surveyed).