Turkey’s ruling Justice and Development Party on Sunday 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, since last month’s referendum removed a constitutional requirement that presidents be neutral and cut ties with their political parties.

Erdogan welcomed the tens of thousands of people outside the arena.

“My dear fellow travelers … we were separated but today we are together once again,” he said.

Erdogan and the AKP won a narrow victory on the April 16 referendum that will transform Turkey’s parliamentary governing system to an executive presidency.

Critics said the vote, which took place under a state of emergency imposed in the wake of last year’s failed coup, was marred by allegations of election fraud.

Most of the constitutional changes won’t take effect until after the next presidential and parliamentary elections, slated for Nov. 3, 2019.

Three amendments, however, have automatically come into effect, including one that allows Erdogan to return to his party. Others are the repeal of military courts and a restructuring of Turkey’s board of judges and prosecutors.

Erdogan was forced to cut his formal ties to the AKP when he became the country’s first directly elected president in 2014 – but he still rallied for the party anyway.

AKP officials and supporters from across the country were at the congress, waving flags to songs about Erdogan and the AKP. Banners read “the leader of change, the nation’s leader.”

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