France has barred four Islamic preachers from entering the country to attend a Muslim conference in Paris.
The French government says the four preach hate and violence and, in the current context, present a strong risk of upsetting public order.
A fifth preacher and an Egyptian cleric had already been banned.
President Nicolas Sarkozy ordered a crackdown on radical Islamists after an al Qaeda-inspired gunman killed seven people last week.
The Union of French Islamic Organisations, which invited the clerics to the conference, says none of them advocates violence and the Government's decision is based on total ignorance.
Mr Sarkozy and his UMP party, campaigning hard to win votes from the far-right National Front, have stressed divisive issues such as halal food and Islamic radicalism in their campaign for the two-round presidential election on April 22 and May 6.