From Picardy, a northern land marked by its bloody past from the Hundred Years War to the Battle of the Somme, to eastern Alsace and Lorraine, twice reclaimed from Germany, several historic regions could lose their boundaries and their names.

Even Paris could face its most dramatic transformation since the 19th century if Sarkozy pursues the reform being proposed to him, absorbing poor suburbs where youths rioted for weeks in 2005 into a new "Greater Paris" entity.

The opposition have cried foul, alleging political motives behind the shake-up, while in the regions that face being swallowed by their neighbours passions are running high.

"I say no to the carve up of Picardy," said pensioner Gilbert Duvivier, of Amiens, capital of the northern region.

"Picardy is a language, a history, a culture. We don't want to be sacrificial lambs," said Duvivier during a morning walk by the city's enormous gothic cathedral, a World Heritage site.

His friend Roger de Winter was equally indignant.

"Go and ask an Australian or an Englishman who fought on the Somme if Picardy means nothing to them," said de Winter.

What Sarkozy wants is to simplify France's complex system of regional, sub-regional and local bodies, often likened to a "mille-feuilles", a cake made from layers of pastry and cream.

"COSTLY AND INEFFICIENT"

There are 22 regions made up of 96 smaller 'departements', each of which contain hundreds of municipal bodies. At each level are elected representatives with different roles. About half of public spending in France is by these local bodies.

Atop the system sit the French state and the European Union. But France needs to cut down on its public spending and Sarkozy has called the layers "costly and inefficient".

He set up a committee in October to study ways to make the system simpler and cheaper. The experts will present 20 proposals to him on Thursday, which he may or may not endorse.

Among their ideas, which are already public, is to reduce the number of regions to 15 to cut down on official bodies. Picardy would disappear, split between three neighbours.

"It would be a loss of identity for us," said Marie-Astrid Lalo, one of the artists at "Ches Cabotans d'Amiens", a puppet theatre that keeps alive a local tradition going back 200 years.

Having survived competition from television and cinema that almost killed it in the 1960s, Ches Cabotans has gone from strength to strength in recent years, acquiring a new theatre in central Amiens and drawing thousands of children every year.

Lafleur and Sandrine, the two main characters in the puppet shows, speak in the old Picard language, and Lalo said interest from the children in their heritage had never been stronger.

"Don't touch my Picardy!" pleads an online petition that has been signed by 60,000 people since it was launched on Feb. 3.

But there is more at stake than local pride and culture.

The mayor of Amiens, Gilles Demailly, says the regional council, which would disappear under the reform plan, is an engine of growth that funds research and attracts private firms.

"The country is facing a serious economic crisis. We should be putting all our energy into fighting unemployment, not launching into a reform that is very far from the concerns of the people," Demailly told Reuters in his city hall office.

POLITICAL AGENDA

In the latest regional elections, the Socialists won control of 21 out of 22 regions. They say the covert aim of the proposed reform is to weaken a tier of government that is in their hands.

The committee denies this and proposes that the reform should come into force in 2014, after the next regional polls. It says the changes would cut the number of regional elected officials to 4,000 from 6,000, saving much-needed public funds.

But Alsace and Lorraine say they have separate identities and reject the proposal that they should merge.

Brittany, in the west, faces a fratricidal struggle between its current capital, Rennes, and the rival city of Nantes which would join the region if the reform goes ahead. With jobs and prestige at stake, the fight to lead the region would be fierce.

Paris could face the most radical changes since Baron Haussmann ploughed through cramped medieval neighbourhoods in the 1850s and 60s to create its tree-lined avenues.

"Paris is suffocating in its current boundaries. It is stuck within limits that were set in 1859," Jacques Julliard, a member of the expert committee, told Reuters.

Under one of the 20 proposals, the Paris department, which includes the city itself but no suburbs, would merge with three adjacent ones to form a new Greater Paris. Julliard said this would allow unified transport policies and boost the population of Paris to 6 million from 2 million.

The plan is a political minefield, however, because Paris and the affluent department to its west, the Hauts de Seine, would find themselves joined with the much poorer Seine Saint Denis district and presumably have to pool resources.

Seine Saint Denis is home to several of the suburbs where riots took place in 2005. Hauts de Seine is home to Neuilly, the rich suburb where Sarkozy was mayor for 19 years.

"It is an idea that disturbs many people," said Julliard, chuckling. "We are tackling some real political fiefdoms."