French President Francois Hollande took a sideswipe at ex-economy Minister Emmanuel Macron on Wednesday, saying members of the government who had resigned to prepare to run against him in next year's presidential election had forgotten their duty.

"Ministers who quit a government, in which they had the opportunity to change France, had the levers in their hands to influence economic and industrial policy, save jobs, shore up entire sectors, address problems in schools or housing, well I think that's akin to forgetting what politics is all about," he said in an extract from an interview with the magazine L'Obs.

Macron, a 38 year-old unelected former adviser to Socialist Hollande who became economy minister in 2014 and is among the most popular politicians in France, has set up his own political movement.

He resigned from the government in August to prepare a potential presidential campaign. Another former economy minister, Arnaud Montebourg who preceded Macron in Hollande's government, is also planning to run in the election next April.