Polls have opened for Turkey’s high-stakes presidential and parliamentary elections, which could consolidate President Recep Tayyip Erdogan’s hold on power.

Voters began gathering outside polling centres to cast their ballots in the elections which complete Turkey’s transition to a new executive presidential system that was approved in a controversial referendum last year.

Mr Erdogan, 64, is seeking re-election for a new five-year term with vastly increased powers under the new system, which he insists will bring prosperity and stability to Turkey, especially after a 2016 failed coup attempt.

Turkey ElectionsMuharrem Ince, presidential candidate of Turkey’s main opposition Republican People’s Party (Emrah Gurel/AP)

His ruling Justice and Development Party, or AKP, is hoping to retain its majority in parliament.

Mr Erdogan — who has been in power since 2003 — is however facing a more robust and united opposition, which has vowed to return Turkey to a parliamentary democracy with strong checks and balances.

It has condemned what it calls Erdogan’s “one-man rule”.

Five candidates are running against Mr Erdogan in the presidential race.

Although Mr Erdogan is seen as the front-runner, he must secure more than 50% of the vote for an outright win. If the threshold is not reached, a runoff could be held on July 8 between the leading two contenders.

Mr Erdogan’s main challenger is 54-year-old former physics teacher Muharrem Ince, who is backed by the centre-left main opposition Republican People’s Party, or CHP, and has wooed crowds with an unexpectedly engaging election campaign.

His rallies in Turkey’s three main cities of Istanbul, Ankara and Izmir drew massive numbers.

Turkey will also be electing 600 politicians to parliament — 50 more than in the previous assembly.