By Alasdair Sandford
BBC News, Paris
Christine Lagarde, the country's first female minister for finance and the economy, says it is time for French people to "roll up their sleeves" and stop thinking about holidays.
The former international lawyer, impressed by the work ethic during her time in the US, is intent on instilling the same spirit in her countrymen and women.
French minister Christine Lagarde wants to transform the work culture
Her approach is calm and conciliatory, bearing little resemblance to the fire and brimstone of her boss, Nicolas Sarkozy.
Yet Christine Lagarde shares the president's convictions when it comes to the French and the world of work.
Until three years ago she was chairman of the law firm Baker and McKenzie, whose main offices are in Chicago.
Her entry into French politics was sudden.
Called up by the former government of Dominique de Villepin, she left the US on a Tuesday afternoon and was at her desk as trade minister the following morning.
She says she was struck on her return by an "ethical change" in the French.
"Instead of thinking about their work, people were thinking about their weekend… organising, planning and engineering time off," she says.
Not that Christine Lagarde believes that life should be "work and nothing else".
Mr Sarkozy's proposed reforms have prompted strikes across France
Looking out from her office window in the huge Soviet-style finance ministry, she points out the barges on the River Seine below - a reminder she says, of how slow things can be when other events are moving at high speed.
Making rapid progress recently has been the minister's pet project, a bill to modernise the French economy.
Last week it passed its first reading in the National Assembly and will shortly go before the Senate.
"More enterprises and more competition" were the objectives, she told parliament earlier this month, in order to obtain three concrete results: "more growth, more jobs and more purchasing power".
Christine Lagarde's task is to sell some of the most challenging reforms of the Sarkozy era to the French people.
Her call for harder work, as well as the measures contained in the economy bill, can touch a raw nerve.
In the old walled town of Lectoure in south-western France, traders come from the surrounding countryside each Friday to sell their products at the market.
Many work long hours, the epitome of Mr Sarkozy's desire for a "France of early risers".
The suggestion that people need to roll up their sleeves does not always go down well.
"I invite Mrs Lagarde to come here and to see how it is from Monday till Sunday," says Laurence Zakine, who runs an antiques store.
She says she works seven days a week, for a maximum of 1000 euros (£791) a month.
The houses in Lectoure back onto small tidy shops along the main street.
The government's plans to shake up the retail industry have brought fears that "more competition" will threaten livelihoods.
Laurence Zakine believes the measures will mainly benefit big business.
"If all the time we go to supermarkets we won't have any more bakeries, we won't have any more butchers, so we have to save these old and small shops."
"Now we clearly don't want that," is Christine Lagarde's response.
"We want to maintain the activities that are so typical of French villages and small towns."
The bill includes measures to strengthen the hand of producers, and increase access to funds for small traders.
The minister argues that the government aims to invigorate town centres, not destroy them, by counterbalancing the power of huge out-of-town hypermarkets so common in France.
"Mobilising the entrepreneur" is another bold objective, especially in a country reputed for favouring over-protected jobs in the state sector.
The bill aims to tackle red tape and encourage small business.
The minister is confident the French will grasp the nettle.
"If you say, 'Would you like to be an entrepreneur?' they might be terribly intimidated," she says. "But if you say 'Would you like to set up a little business on the side?' or 'Would you like to be your own boss?' then the answer is likely to be different."
Critics have attacked the government's approach as "propaganda" promoting "the law of the jungle".
Christine Lagarde acknowledges that France is not used to the new "culture", but believes a momentum has been created that will drive through change.
"It's going to reform the way we conduct business, the way in which work is valued, and the way in which people relate to money," she says, "and it's good."
Getting The French To Work will be broadcast on Monday 23 June at 1100BST on Radio 4