* Sarkozy to press ahead with stripping citizenship bill
* Measure to apply to attackers of police, not polygamy
* Critics say bill may be unconstitutional
PARIS, Sept 6 (Reuters) - President Nicolas Sarkozy vowed on Monday to press ahead with plans to strip French citizenship from immigrants who attack police, but ruled out that punishment for those who practice polygamy or promote female circumcision.
Sarkozy first proposed reversing the naturalisation of immigrants convicted of endangering the lives of police in July in response to three days of urban riots in the southern city of Grenoble after police shot dead a suspected armed robber.
But the president’s proposals, and a separate call by his Interior Minister Brice Hortefeux to strip the nationality of polygamists and female circumcision advocates, have been fiercely criticised by the opposition and some legal experts.
In a statement issued after Sarkozy met with ministers responsible for security, justice and immigration, his office said the president had underlined his determination to implement the steps he announced in July “as soon as possible”.
The office specified that the punishment would apply to immigrants who had gained French nationality in the last 10 years and who “endanger the life of a person in charge of public security, in particular the police and gendarmes.”
Sarkozy’s Immigration Minister Eric Besson had expressed doubts about putting his cabinet colleague Hortefeux’s proposals into law and those plans have been dropped.
Still, legal experts say the Constitutional Council could decide to throw out a government bill that critics say runs counter to the Article 1 principle that all French citizens are equal before the law, regardless of race, creed or origin.
“It seems to me to pose real problems,” Gerard Larcher, president of the Senate, the upper house of parliament, and a member of Sarkozy’s UMP party, told the newspaper Le Monde.
“The real question is: would it really improve French people’s security?”
The constitutional watchdog did uphold an exception in the 1990s allowing the removal of French citizenship for immigrants convicted of acts of terrorism.
Left-wing and intellectual critics accuse Sarkozy of playing to racist sentiment by lumping violent crime and immigration together, and creating two classes of citizenship.
An opinion poll for the pro-goverment Le Figaro published shortly after his speech found nearly three-quarters of voters supported his hard line proposals.
However, subsequent polls in left-wing media have suggested a small majority disapprove of revoking the nationality of criminals who have been citizens for less than 10 years.
Tens of thousands of demonstrators protested in several cities on Saturday against Sarkozy’s security crackdown, which has included the highly publicised rounding up and expulsion of illegal Roma migrants. The government called the protest a flop.
Political analysts say Sarkozy is talking tough on crime and immigration to try to win back disenchanted conservative and blue-collar voters, tempted by the extreme-right National Front, ahead of a re-election bid in 2012.
They say he is calculating that despite his relative failure to reduce violent crime in eight years as interior minister and head of state, voters trust him more than the Socialist opposition on security issues.
reporting by Yann Le Guernigou, writing by Paul Taylor, editing by Noah Barkin