The head of Turkey's main Kurdish party has addressed lawmakers in the Kurdish language, defying a Turkish ban on the practice. The live television broadcast of his speech was cut and the government has strongly criticized his action. Although Kurds make an estimated fifth of the country's population,  strict controls exist on the use of their language.

Ahmet Turk, the leader of the pro Kurdish Democratic Society Party or DTP, is at the center of a political storm. He began his speech in parliament Tuesday by speaking in Turkish to members of his party, and later switched to Kurdish.

He said, "because it is the United Nation's day of world's indigenous languages and because of the still existing pressure on the Kurdish language and also to remind people that the fear of  'native languages' is an artificial one, and because of our belief in the beauty of languages and the fraternity of people, I will try to continue my speech in Kurdish."

To a standing ovation from his deputies Turk starting speaking Kurdish. But after only a few words, the live broadcast by the state run channel was cut.

A presenter apologized saying they could no longer continue broadcasting as Turkish was the only language allowed to be used in parliament. 

But Turk continued speaking in Kurdish for 11 minutes. His speech has drawn widespread political condemnation.

A government minister said it was a provocation, while the opposition National Action Party claimed it was a threat to the integrity of the country.

Speaking Kurdish in public was entirely forbidden until 1990.  The language continues to be barred in parliament and in state education. But under pressure from the European Union, controls on the Kurdish language have gradually eased.

Last month a state run channel delivered entirely in Kurdish was launched. Prime Minister Recep Tayyip Erdogan even spoke a few words of Kurdish on its opening. The channel is reported to be popular among many Kurds.

The governing Justice and Development Party, or AKP, is using that popularity in next month's local elections. For the first time, the party is challenging the pro Kurdish DTP for control of Diyarbakir, the main city in the predominantly Kurdish southeast region of Turkey.

The decision by DTP leader Ahmet Turk to speak Kurdish in parliament is being seen by some analysts as an attempt to underline his party's credentials among Kurds in the region. Speaking to reporters after his Kurdish address, Turk remained defiant.

"If our prime minister can speak Kurdish, why can't I address my own people in Kurdish? Now certain limits have to be ended," he said.

Turk could now face prosecution under Turkey's strict laws protecting the integrity of the state. The country's constitutional court is already deliberating whether to shut down his party under the same laws.  Analysts say its unlikely Turk would face jail but his speech is expected to strengthen the prosecutor's call to punish the Kurdish DTP party.