Top Paris art galleries and the Palace of Versailles have weighed in against an unpopular push to extend wealth tax to art, complaining in a letter to the government that such a move could drive historic collections out of France.

The daily Liberation printed an excerpt from a letter it said was signed by the heads of the Louvre, Versailles, the Musee d'Orsay, the Pompidou Centre and others and sent to the culture minister and President Francois Hollande, saying the tax would crush the art world.

"There's a risk that France will contribute to the disappearance of historic collections that have been passed down through the generations," Liberation quoted the letter, written on Friday and also signed by several city mayors, as saying.

Spokespeople for the various art galleries could not be reached for comment.

Prime Minister Jean-Marc Ayrault appeared to sound the death knell on Tuesday for the push for art works worth over 50,000 euros ($64,700) to be included in assets used to calculate a person's fortune, saying the Socialist government opposed it.

"Artworks will not be included in the calculation of wealth tax. That's the government's position," he told Europe 1 radio.

Budget Minister Jerome Cahuzac cautioned that the proposal was not buried yet.

"We will have a frank discussion with the Socialist group. It is possible for a government to be beaten by its parliamentary majority," he told France Inter radio.

Currently, only assets like real estate or cash savings count towards wealth tax. Net assets of more than 1.3 million euros are taxed at 0.25 percent on top of income tax, and the rate doubles to 0.5 percent for assets above 3 million euros.

Left-wing lawmaker Christian Eckert's idea of including artworks has won backing from the lower house finance committee, sparking cries of indignation as the Paris art world prepares for the opening of its annual flagship art show, the FIAC.

Culture Minister Aurelie Filippetti said last week the government opposed the proposed amendment to the 2013 budget.

With a long tradition of public support for the arts, France has spared works of art from the wealth tax ever since former president Francois Mitterrand introduced the levy in 1982.

Mayors including Martine Aubry of Lille and Betrand Delanoe of Paris, said art collectors were vital to encourage artistic creation and preserve France's artistic wealth, Liberation said.

Hollande's first budget has already antagonised the rich by imposing a new 75 percent tax on income above 1 million euros and he has had to promise an exemption for small business owners on a new capital gains tax hike following an online protest.

($1 = 0.7730 euros)