Turkey's nationalist MHP opposition, riven by a leadership battle, will hold an extraordinary congress sought by party dissidents on June 19, a court-appointed organising committee said in a statement on Monday.

The congress is aimed at resolving a leadership dispute between MHP leader Devlet Bahceli and dissident MHP members and could complicate President Tayyip Erdogan's efforts to push through reforms boosting his powers.

Polls suggest Bahceli's removal could lead to a surge in support for the MHP. Bahceli himself set a date of July 10 for an extraordinary congress after a court ruled the assembly should go ahead, saying he will stand again for leadership.