Czech Roma have demonstrated in the past against perceived racism
The Czech government has expressed outrage over the broadcast of an anti-Roma (Gypsy) campaign advert by a far-right group on national television.
The head of Czech Television, Jiri Janecek, said the National Party (NS) video would not be broadcast again.
Interior Minister Martin Pecina has said he is now seeking to ban the NS.
The NS advert spoke of "a final solution to the Gypsy issue" and carried the slogan "Stop Favouring Gypsies" over images of Roma.
Prime Minister Jan Fischer and Human Rights Minister Michael Kocab said they considered the NS video illegal.
Earlier, a spokesman for Czech Television said that by law, it had no right to alter any party's election advertisements.
Mr Fischer said the advert evoked "the [Nazis'] Final Solution of the Jewish question during World War II", the AFP news agency reported.
Campaigning has just started in the Czech Republic for next month's European Parliament elections.
Roma, many of them impoverished, have long alleged that they suffer discrimination in the Czech Republic.
Mr Fischer has pledged to address the issue of Roma rights.
Last year his centre-right predecessor, Mirek Topolanek, tried to get a ban imposed on another far-right group, the Workers' Party, but in March this year a court refused to do so.