French ministers have disclosed their personal wealth for the first time in a move that President Francois Hollande hopes will restore confidence in his scandal-hit Socialist government.

The assets of 37 ministers and of Prime Minister Jean-Marc Ayrault were published online on Monday on a specially created website.

The move was part of Hollande's new rules for financial conduct unveiled last week after the revelation that France's top tax collector was himself dodging taxes.

Critics say the Socialist government listing of ministers' personal wealth is just a political show.

With the economy stagnant, unemployment on the rise and the government cutting spending, senior officials admit the move is risky and could create resentment by unmasking several millionaire ministers.

But the government has pushed ahead in the hopes the measure will help limit the damage of the scandal over tax fraud charges laid against ex-budget minister Jerome Cahuzac after he admitted having a secret Swiss bank account.

Politicians on the right and left have criticised the move and the government expects a tough battle when it attempts to have the disclosure rule extended to parliamentarians in a bill to be introduced on April 24.

The head of the main opposition right-wing UMP, Jean-Francois Cope, said on Monday that the measure would only create tensions in French society.

"The only consequence of all of this voyeurism will be that a certain number of people - businesspeople, artisans, professionals - will no longer want to engage in public life," Cope told BFMTV.

'Difficult to understand'

Close scrutiny is expected to fall on several ministers suspected of having significant wealth, including Laurent Fabius, foreign minister, a well-known art lover whose father was an antiques dealer.

The minister for the elderly, Michele Delaunay, disclosed on Monday family assets of 5.4m euros ($7m).

"It is significant wealth," she told the daily newspaper Sud-Ouest.

"It will be difficult to understand for the majority of the French, who are facing hard times."

Delaunay, the former head of a cancer clinic, said that she and her husband had acquired their four homes and significant savings over lifetimes of work as well as through inheritance.

She said that revealing their assets had been a real challenge, but she supported the disclosure measure.

"It is probably a necessary step towards a real battle against tax evasion and fraud," she said.

"If we had not taken it, in the context of Cahuzac, it may have been seen as a desire to protect certain people."

Hollande will not make a new declaration because he already released details of his wealth when elected president.

At the time he declared $1.53m in assets, including a house in the southern town of Mougins and two apartments in Cannes, though he is still paying 1,500 euros a month on loans.