Supreme Court prosecutors asked the Constitutional Court to ban the Democratic Society Party (DTP), according to court documents.

The DTP was founded in 2005 and has its origins in another pro-Kurd party which was also ordered to disband because of alleged links to the outlawed Kurdistan Workers Party (PKK).

"The party in question has become a base for activities which aim at the independence of the state and its indivisible unity," said the prosecution application, quoted in a Supreme Court statement.

The legal action came amid heightened tensions with Iraq caused by Turkey's threat to launch cross border attacks on PKK bases.

DTP deputy Sirri Sakik, and a militant Kurd activist, said the action by the authorities was "not really a surprise".

"It is a step backwards in the country's democratic process as well as the process of integration with the European Union," Sakik told AFP.

"Turkey is becoming a cemetery of banned political parties. Closing a group does not resolve the problem," he added.

About 20 pro-Kurdish candidates who stood as independents in the national election in July grouped together in parliament under the DTP banner.

Pro-Kurdish parties have never, in their own right, got past the 10 percent of the vote needed to secure seats in parliament.

The DTP has been accused by the government, opposition and army and the Turkish media of being the political wing of the PKK, which has been fighting the Turkish army since 1984 and is labelled a terrorist organisation by Turkey, the United States and other countries.

Senior prosecutor Abdurrahman Yalcinkaya has been working for the past year on a case against the DTP, which held a congress in Ankara last week to elect a leadership.

The legal procedure against the DTP is expected to take several months.