ISTANBUL (AP) — Turkey's ruling Justice and Development Party has kicked off a congress to re-elect President Recep Tayyip Erdogan as its chairman after last month's referendum.

Erdogan will return to lead the party he co-founded after Sunday's extraordinary congress in Ankara. Last month's referendum on constitutional amendments removed a requirement that presidents be neutral and cut off ties with their political parties.

Supporters from across the country are meeting in the arena, waving flags to songs about Erdogan and the AKP. Banners read "the leader of change, the nation's leader."

The congress is expected to last all day, with speeches by the current party chairman, Prime Minister Binali Yildirim and Erdogan, to be followed with voting.