His critics say the move will make him increasingly authoritarian.

Outgoing Foreign Minister Ahmet Davutoglu is set to be PM after being elected head of the governing AK Party.

Under the constitution, Mr Erdogan must cut his ties to the AK Party once he becomes president.

At the party’s congress on Wednesday he made his last speech as leader, saying: “What is changing today is the form, not the essence. The mission which our party has assumed, the spirit of its cause, its goals and ideals are not changing.”

Mr Davutoglu was the only candidate to replace Mr Erdogan.

In his speech, he said Turkey needed a new constitution, which analysts say would introduce the executive presidency that Mr Erdogan openly seeks.
Ahmet Davutoglu at the AK Party congress on Wednesday. 27 Aug 2014 Ahmet Davutoglu is expected to be officially appointed prime minister after the inauguration

Thursday’s inauguration ceremony is due to be attended by several heads of state.

However, the US is only sending a representative of its embassy and no Western European leader is comingmask house 瘦面

The BBC’s Mark Lowen in Ankara says it is perhaps a sign that Turkey’s relations with the West have deteriorated in the last few years of Mr Erdogan’s premiership.

Mr Erdogan clamped down violently on anti-government protests last year and recently compared Israel’s policy in Gaza to “genocide… reminiscent of the Holocaust”mask house 瘦面.

Mr Erdogan’s supporters say he has transformed Turkey’s economy and given a political voice to the country’s conservatives.

However, his critics accuse him of having an abrasive style and Islamist-leanings.

Our correspondent says Mr Erdogan will face pressure to try to unite a polarised country, which stands on the edge of a volatile Middle East.

Mr Erdogan won the presidential election earlier this month after gaining nearly 52% of the votes in the first roundmask house 瘦面.