French ministers revealed their private wealth en masse last night as part of a drive by the President François Hollande to impose transparency on a stubbornly secretive political culture.

The Socialist government was revealed to contain several multi-millionaires, including the Foreign minister, Laurent Fabius, who is worth more than €6m (£5.1m), and the minister for Elderly People, Michèle Delaunay, who is worth just over €5m.

The exercise was part of a drive to “moralise” French politics announced by Mr Hollande last week in the wake of the Jérôme Cahuzac tax evasion scandal. The 38 ministers were ordered by the President to reveal their total family wealth – bank balances, property, business holdings, cars, jewels and art works – by yesterday evening. To the dismay of both left- and right-wing politicians, a law will be enacted in the next couple of months to oblige all parliamentarians to do the same.

One centre-right parliamentarian complained yesterday that it was like asking him to “show off his wife naked”. The French press spoke of a “governmental Crazy Horse saloon”.

The French government’s official website has rarely been so popular. The site was inundated with hits at 5pm – the time originally given for the ministerial striptease. The announcement had to be delayed for an hour.

President Hollande insists that a new openness is necessary in a country in which the private dealings of politicians – and even their expenses – have rarely been subject to official scrutiny. Mr Hollande is desperately trying to regain the moral high ground – or, his opponents suggest, trying to change the subject – after his former Budget minister admitted two weeks ago that he had been cheating on his taxes for two decades.

Mr Cahuzac, 60, once a wealthy cosmetic surgeon, was until last month the minister in charge of spending cuts and cracking down on tax evasion. After four months of denials, including lies to the President and parliament, he admitted that he had regularly hidden money in bank accounts abroad and still held €600,000 in Singapore.

Mr Hollande says public declaration of politicians’ wealth will help to reassure the public that the majority of their elected officials are not crooks. In future, it will be possible, he says, to check whether ministers and parliamentarians have accumulated wealth while in office.

The President did not join in last night’s exercise. As a presidential candidate last year, he had revealed that he had property and savings worth about €1.1m

The leader of the centre-right opposition, Jean-Francois Copé, has dismissed the revelations as a form of “voyeurism”. He accuses Mr Hollande of inviting the French public to judge politicians not by their honesty or competence but by their wealth.

Some senior politicians on the Left, including the speaker of the National Assembly, Claude Bartolone, have also expressed deep reservations. Mr Bartolone says that forcing parliamentarians to reveal their family wealth will drive all but the most driven, career politicians out of public life.

France, traditionally reluctant to pry into private fortunes of politicians, will now become one of the EU countries where politicians are the most easily scrutinised. In Britain, MPs have to disclose their private earnings but not their total worth.

Advance speculation had concentrated on the possible wealth of the Foreign minister, Mr Fabius, whose grandfather was one of the most succesful Paris art dealers of the 20th century. As expected, he turned out to be the wealthiest member of an, on the whole, modestly well-off Socialist government.

To general surprise, however, he turned out to be only sightly wealthier than the realtively obscure minister for the Elderly, Ms Delaunay. She made her money as one of France’s leading cancer specialists before turning to politics.

The most minute declaration was made by the Justice minister, Christiane Taubira, who listed a string of low-value houses and fields in her native French Guiana, a Hyundai car and three bicycles.

Ministers and their declarations

Michèle Delaunay, 65, minister for Elderly People

Ms Delaunay, formerly a leading cancer specialist, revealed that she and her husband were worth €5.4m. This included four properties worth €3.1m and €200,000 in paintings and antique furniture. “It’s a great deal of wealth and difficult to explain to the majority of French people who are struggling,” she said.

Jean-Marc Ayrault, 63, Prime Minister

A former German teacher and long-time mayor of Nantes, Mr Ayrault declared himself to be worth €1.55m. This consisted mostly of two homes in Nantes and Brittany jointly owned with his wife – and a 1988 Volkswagen Combi worth €1,000.

Christiane Taubira, 60, Justice minister

Ms Taubira, a life-long politician, revealed modest property holdings in her native French Guiana, including two “traditional” houses worth €75,000 and €70,000. She revealed that she owned a 2008 Hyundai worth €13,000 and three bicycles, worth a total of €900.

Laurent Fabius, 66, Foreign minister

Fabius comes from a wealthy art-dealing family and fantasies have long existed about his personal riches. In the event, he declared a comparatively modest €6.07m, consisting of a €2.7m apartment in Paris, two country homes and a collection of antique furniture.

Aurélie Filippetti, 40, Culture minister

She announced in advance that she owned only a flat in Paris and a David Beckham football shirt. In her official declaration yesterday, she mentioned a heavily mortgaged, 71sq m flat in the fifth arrondissement worth €710,000 – but she failed to declare the shirt.