France's President Jacques Chirac yesterday called for the "indelible stain" of slavery to be remembered in a national day of commemoration on May 10, the first of its kind in Europe.

Mr Chirac described the holiday, marking the day the French senate passed a law recognising slavery as a crime against humanity in 2001, as a chance to "show the way" to other countries by exhibiting France's "glory and strength".

"The grandeur of a country, it is to assume all its history. With its glorious pages, but also its more shady parts," said Mr Chirac, in a speech designed to cool the racial tensions caused by last year's riots and defuse a bitter political debate over French colonial history.

He promised to fight modern forms of slavery by allowing companies that knowingly used forced labour in any country to be prosecuted in French courts. He also proposed a "European or international initiative" forcing companies to respect "basic worker rights" in poorer countries.

Slavery is a thorny issue for many of the world's richest countries and African states have long been pushing them to make a formal apology.

Mr Chirac yesterday recalled France's role in banning slavery - once in 1794, before it was reintroduced by Napoleon in 1802, only to be finally outlawed for good in 1848. "The (French) Republic can be proud of the battles it has won against this ignominy."

However, not everyone in France welcomed the move. Historians are upset about the government's attempts to dictate how history should be taught in schools.

A petition, entitled "freedom for history" and signed by 600 historians, was published this month calling for the repeal of laws imposing a certain view of history, including a 1990 law on racism, a 2001 law recognising the Armenian genocide and the 2001 law on slavery.