By Brian Rohan

PARIS, March 28 (Reuters) - French President Nicolas Sarkozy may have taken two ministers from immigrant families with him when he dined with Britain's Queen Elizabeth this week, but rights groups say minorities are badly underrepresented in French politics.

Justice Minister Rachida Dati, who comes from a poor North African family, and Senegalese-born junior Foreign Minister Rama Yade were with the president at a state dinner at Windsor Castle on Wednesday.

But a report this week on this month's local elections shows that in day-to-day politics, parties have yet to accept ethnic diversity on their tickets.

Just two mayoral posts went to candidates with what in French are called "diverse" backgrounds, and only around 2,000 city council seats of a total 520,000 were won by minority candidates, the National Committee for Diversity report showed.

"It's unbelievable -- Barack Obama is running for president in the United States, but here we're still fighting for city council seats," said Patrick Lozes, a spokesman for the group.

"There has been progress since local elections in 2001, but we are still grossly underrepresented in a country where close to 20 percent of the population are ethnic minorities," he told a news conference on Wednesday while presenting the report.

Dati and Yade are the two most prominent examples of Sarkozy's determination to open up his government to people from outside the traditional white, male political class but the obstacles to wider participation by the minorities are huge.

CLOSED ARENA

Official statistics on France's ethnic make-up do not exist under the country's 'Republican' system of government, which considers the tracking of such figures an act that would exacerbate splits in society.

But with immigration a hot political topic, driven by sporadic violence in the bleak suburbs where many immigrants settled -- and where unemployment among their children is rife -- calls have grown for new ways of looking at the issue.

Romain Garbaye, a teacher at the Sorbonne University in Paris who has written about minorities' access to local politics, said France lagged other countries.

"Local politics is generally a very closed arena ... And we haven't had any major recruitment of minorities here like the massive drive the Labour Party had in Britain to get them elected," he said.

France has only one black member of parliament from the mainland -- Socialist George Pau-Langevin, who was elected in May -- although there are others from its overseas territories.

As well as her ministerial post, Dati also won election as mayor of the chic 7th arrondissement (district) in Paris in the March election. But politicians from both main parties say such victories are still largely symbolic.

"One high-profile victory does not make up for overall low numbers," said Abderrahmane Dahmane, an advisor to Sarkozy and member of his conservative UMP Party. (Editing by Janet Lawrence)