Ahmet Turk, head of the Democratic Society Party (DTP), the main pro-Kurd party, was speaking to his party's parliamentary group about UNESCO's international day of native languages, he said.

He started speaking in Turkish and then switched to Kurdish, but after a few minutes the public television channel which broadcasts activities in parliament cut off the transmission.

Turk received a standing ovation from about 20 members of his party but other political parties denounced his initiative, local media reported.

"The official language of Turkey is Turkish," said the head of the national assembly, Koksal Toptan, citing Turkish law which requires the use of the Turkish language in parliament and public offices.

"The meeting should have been conducted in Turkish," he told reporters, according to the Anatolia news agency.

Some lawmakers saw Turk's action as a political manoeuvre ahead of municipal elections set for March 29.

The DTP is already under threat of being banned because of its alleged ties with the armed rebels of the outlawed Kurdistan Workers' Party (PKK) and, according to analysts, the speech in Kurdish could strengthen the hand of prosecutors and judges in charge of the case.

Turkey in recent years has made major cultural reforms for the Kurdish community, with Ankara's view of eventually joining the European Union.

Ironically, the public broadcaster TRT launched at the start of this year a channel entirely in the Kurdish language.