President Jacques Chirac ordered the hulk of the decommissioned carrier to be towed back to France from the Indian Ocean after the official French state watchdog declared the old ship to be a 27,000-ton piece of "industrial waste".

The ruling ended a six- week chapter of blunders and misleading statements as the French military attempted to export the Clemenceau to India for removal of residual asbestos, and for scrapping.

The 45-year-old ship, once the pride of the French navy, left Toulon under tow on 31 December and is now circling in the Indian Ocean.

Following yesterday's ruling by the Conseil d'Etat in Paris, the Clemenceau will be towed back to the Mediterranean, incurring, once again, multimillion euro "compensation" charges for passing through the Suez canal.

The ruling is a triumphant vindication for Greenpeace and three other ecological groups which had protested from the beginning that the export of the Clemenceau broke European Union rules.

The French government insisted that the Clemenceau was still a warship, despite the fact that it had been de-commissioned from the French fleet in 1997.

Greenpeace, and others, said that the ship was industrial waste and contained far more asbestos than the French Navy had admitted.

They brought a case before the Conseil d'Etat, the supreme arbiter of the legality of government decisions in France, which agreed yesterday on both points and cancelled the export documents.

At the weekend, the French Defence Minister, Michèle Alliot-Marie, had been forced to admit that doubts existed about the amount of asbestos left in the ship. Thirty tons of asbestos could not be accounted for, ministry officials said.

The minister announced on Monday that she was taking legal action against a French contractor which had stripped the aircraft carrier of asbestos in when it was in Toulon.

Opposition politicians - who had been relatively quiet until now - described the Clemenceau affair yesterday as a "fiasco"which had exposed the country to "international ridicule". François Hollande, the first secretary of the Socialist Party, said that he would press for an official inquiry.

President Chirac, who visits India at the weekend, and faced the prospect of demonstrations and humiliating questions on his arrival, decided yesterday to cut his losses.

Within minutes of the Conseil d'Etat ruling, he ordered the aircraft carrier to be returned home.

The Clemenceau - which was known to generations of French sailors as the "Clem" - would be returned to French waters immediately, the Elysée Palace announced. There it would be be placed "in a holding position, in perfect conditions of safety, until a final solution is found for its scrapping".

The whole confusing affair draws attention to a serious, wider problem of the safe scrapping of warships, and merchant ships, built in the 1960s or 1970s with large amounts of asbestos.

All along, the French defence ministry insisted that, as a warship, the "Clem" was exempt from a 1993 European regulation which bans the export of dangerous wastes.

The Conseil d'Etat yesterday ruled that this was not the case. Warships were not exempt from the EU law and, furthermore, a "serious doubt" existed about the amount of asbestos left on board.