PARIS (AFP) - French ministers lining up to publicly declare their personal assets are sparking a revolution in political thinking in France, where experts say it is often easier to talk about sex than money.

Under new measures aimed at restoring public confidence in politicians after a major tax fraud scandal, ministers in President Francois Hollande's government have until Monday to lay out their wealth for all to see.

The government announced the requirement this week in a bid to limit political damage from the scandal surrounding former budget minister Jerome Cahuzac, who is facing tax fraud charges for having an undeclared foreign bank account containing some 600,000 euros (S$972,000).

Some have already come forward, including Health Minister Marisol Touraine who declared a personal wealth of 1.4 million euros based on several properties in Paris.

But the initiative has launched a fierce debate in France, where privacy laws are strict and many consider the move as delving too far into the private lives of public figures.

"In the European Union, there are only two countries where asset declarations for elected officials are not public: Slovenia and France. This speaks volumes about the backwardness of our political customs," said Daniel Lebegue, the head of the French branch of anti-corruption group Transparency International.

French lawmakers have been required since 1988 to submit financial transparency declarations within two months of being elected, but many ignored the requirement and penalties for failing to do so were never applied.

The new measures are part of a package of reforms, including a new financial transparency law expected to be approved by the summer, that the government has promised in the wake of the Cahuzac scandal.

Politicians on both the left and right have criticised the measures, with the head of the main opposition right-wing UMP, Jean-Francois Cope, saying they amount to "voyeurism".

"There is a cultural reluctance towards transparency in France," said Mr Lebegue, noting that for example French lawmakers are not required to provide justification for their use of some 6,400 euros they are granted in monthly expenses.

"Elected officials (in France) feel they embody the public interest and have no accountability until the next election. This is not how a modern democracy should work," Mr Lebegue said.

Criticism of the measure also reflects a wider reluctance among the French to discuss their personal finances, said sociologist Janine Mossuz-Lavau.

"In France we don't know exactly how much our family, friends or neighbours earn and it would be very rude to ask them," she said.

Ms Mossuz-Lavau said that during a 2007 study she conducted on the French and their personal finances, interview subjects "found it much more difficult to talk about money than about sex". She said three factors were at play.

"The French are almost all from a peasant background where money should remain hidden to not arouse jealousy or greed; this is a country with a culture of Catholicism, which is turned toward the poor; and finally the left has retained the Marxist idea that 'greed is bad'," Ms Mossuz-Lavau said.

Some ministers have backed the law, including Culture Minister Aurelie Filippetti who on Wednesday declared on France 2 television that she owned a 70sqm flat and, jokingly, a David Beckham T-shirt.

"In a period of crisis like we've known because of the Cahuzac scandal, we must restore the confidence of the French, so they can see that people in the government and elected officials who represent them live like they do and stop some of the fantasies," she said.