The law won support from both government and opposition benches, and was adopted by a comfortable majority of 287 to 217.

The bill - the product of months of talks between Prime Minister Lionel Jospin and local leaders last year - guarantees teaching of the Corsican language in primary schools, and hands down controversial environmental powers over the island's largely unspoilt coastline.

Deputies had already approved a clause allowing the island's regional parliament to adapt some laws on an experimental basis.

'Time-bomb' claim

A constitutional amendment to make this right permanent is promised if there is no return to separatist violence.

Jean-Pierre Chevenement: Main opponent

Opposition in the Assembly was not as stiff as expected when the bill was first presented last week, with hardline former Interior Minister Jean-Pierre Chevenement - who resigned last year over the bill - mounting the only heart-felt challenge.

He described the changes as a "time-bomb".

Right-wing deputies had argued that the law made an unacceptable exception out of Corsica, but were pacified when Interior Minister Daniel Vaillant unexpectedly announced that some regulatory powers could be extended to other French regions.

When it came to the vote, the bill won support from the Socialists and their Green Party allies, as well as some opposition members. The Communists - also part of Mr Jospin's left-wing coalition - abstained.

President Jacques Chirac's right-wing RPR party, and many MPs from the centre-ground UDF party, voted against the bill.

The measure now passes to the upper house, the Senate.

Coastal tourism

Corsica, which has a population of 260,000, has been prey to sporadic separatist violence since the mid 1970s, but the main paramilitary groups have maintained a ceasefire since the start of last year.

The proposed devolution would mark an important break with the centralising tradition of French politics.

But it would still leave the island with fewer powers than other European regions - such as Catalonia in Spain, the German lander or Scotland - which have substantial autonomy.

Environmentalists have raised concerns about one clause which would grant Corsica a dispensation from a 1986 coastal protection law.

It would allow local deputies to give licences to build tourist facilities along the island's 1,000km (625 miles) of coast.

Partly as a result of the separatist violence, the island has been spared the mass development that afflicts much of France's mainland Mediterranean coast, but activists fear commercial and local political interests could combine to start a large-scale construction programme.