PARIS (AP) -- Critics on Saturday blasted a proposal by conservative French presidential candidate Nicolas Sarkozy to create an immigration ministry, comparing it an institution set up during the Nazi puppet regime of World War II.

In a television appearance Thursday, Sarkozy said he wants a new ministry to oversee questions of immigration and national identity — part of a tough stance on immigration that has become a key part of his campaign.

As interior minister, he has backed two laws to tighten immigration regulations, and he hopes to push through another if he is elected president.

Critics accused Sarkozy of borrowing language from the far right, which often uses the term "national identity" to complain that immigrants are diluting France's national character. Centrist candidate Francois Bayrou said Sarkozy had "crossed a line." Socialist Segolene Royal, Sarkozy's main rival in the April 22-May 6 two-round race, said the proposal was "rather vile." "Never have immigrant workers threatened French identity," she said Saturday. "On the contrary, legal immigrants — who are requested by companies, who often come to France to do the work that the French don't want to do — contribute to economic growth."

"Associating immigration and national identity is a throwback to the darkest periods of our history," Communist candidate Marie-George Buffet said. The MRAP anti-racism group also said Sarkozy was drawing on "the darkest hours" of France's past. Sarkozy, the son of a Hungarian immigrant, said Friday that France should choose its immigrants more carefully. He defended his proposal, saying "identity is not a dirty word."

"France is an open country, but people who come must take into account our values" — such as a division between church and state, equality between men and women and democracy, Sarkozy said.