A DTP spokesman said Friday that members of Sinn Fein and Batasuna, the political wings of, respectively, the Irish Republican Army (IRA) and the Basque separatist ETA, as well as members of the European Parliament, would attend the congress to show their solidarity with the Kurds.

The DTP was set up in November, pledging to work to resolve the long-standing Kurdish conflict in Turkey through peaceful means.

But the party has failed to achieve any breakthrough, amid mounting violence in the southeast by the separatist Kurdistan Workers' Party (PKK).

The DTP has come under fire for sympathizing with the PKK, blacklisted as a terror group by Turkey, the European Union and the United States, and dozens of party members face prosecution for supporting the rebels.

The DTP advocates broader cultural and political rights for Kurds and campaigns for the abolition of a 10-percent electoral threshold required to enter parliament.

At Sunday's congress, the party is expected to amend its leadership system -- which currently has two chairs, a man and a woman -- and bring it in line with Turkish legislation which allows only one person as party leader.

The change is expected to result in Aysel Tugluk, the current chairwoman, withdrawing from the leadership to leave her co-chairman Ahmet Turk, a veteran Kurdish politician, at the helm.

Kurdish politicians in Turkey are routinely regarded with suspicion and often seen as instruments of the PKK.

Keen to boost its bid to join the European Union, Ankara has granted the Kurds a measure of cultural freedoms over the past several years.

The Kurdish conflict has claimed about 37,000 lives since 1984 when the PKK took up arms for self-rule in the mainly Kurdish southeast.