Istanbul (AFP) - More than 53.7 million Turks will be eligible to cast their votes in parliamentary elections Sunday, which could decide whether the country adopts a strengthened presidential system under President Recep Tayyip Erdogan.
The elections are seen as the biggest challenge for the ruling party since it first came to power in 2002 and embarked on a drive to transform the country, with analysts not ruling out that it may have to go into coalition for the first time.
Here is a round-up of the main political forces:
JUSTICE AND DEVELOPMENT PARTY (AKP)
Leader: Ahmet Davutoglu
Slogan: 'They talk, the AKP acts'
Expected position: First
Last election (2011): 49.83 percent
The AKP remains Turkey's dominant political force, but in these elections it has a big challenge on its hands with the economy losing its previous lustre. Under ex-foreign minister Ahmet Davutoglu, the party has missed its charismatic former premier, President Recep Tayyip Erdogan, who to the fury of opponents has recently stepped fully into the campaign. The party is Islamic-rooted and Davutoglu has put religion at the centre of the campaign while promising to modernise Turkey.
RESYSTEMAN PEOPLE'S PARTY (CHP)
Leader: Kemal Kilicdaroglu
Slogan: 'Give your vote, get them out'
Expected position: Second
Last election: 25.98 percent
The party of modern Turkey's secular founder Mustafa Kemal Ataturk, the CHP had looked moribund in recent years and its former leader was sunk by an embarrassing sex tape scandal. Kilicdaroglu has taken on a Mr Clean image and tried to attack the AKP's perceived extravagance, although he is far from the dynamic opposition figurehead that the CHP yearn for. The CHP's campaign has been slick, but they are still expected to be well behind the AKP.
NATIONALIST MOVEMENT PARTY (MHP)
Leader: Devlet Bahceli
Slogan: 'Walk with us Turkey'
Expected position: Third
Last election: 13.01 percent
Founded in the 1960s, the MHP was long linked to the Turkish extreme right, although under leader Devlet Bahceli the party has shifted to cultural rather than ethnic nationalism. A new emphasis on religion brought it closer to the AKP and the two could be potential coalition partners should the ruling party fail to win an overall majority. But the MHP rejects the AKP's efforts to make peace with Kurdish rebels. With a hard core of committed voters, MHP support is expected to hover between the mid to high teens.
PEOPLE'S DEMOCRATIC PARTY (HDP)
Co-leaders: Selahattin Demirtas, Figen Yuksekdag
Slogan: 'We're on our way to the Meclis (parliament)'
Expected position: Fourth
Last election: Stood as independents
The pro-Kurdish HDP has attracted huge attention in this campaign, led by the charismatic Demirtas, the sole Turkish politician to rival Erdogan's rhetorical skills. They have sought to broaden appeal beyond their natural Kurdish base in the southeast to secular Turks, women and gays. Their challenge is to breach the 10 percent vote minimum needed to win seats and their presence, if they send MPs to parliament, could block the AKP's dreams of constitutional change.
TURKEY'S PARLIAMENTARY VOTE AT A GLANCE
Turkey elects its MPs according to a proportional representation system from lists in each of its 81 provinces. However the 10-percent threshold -- criticised as being one of the harshest election rules in the world -- means it will make a huge difference if the HDP wins seats.
The 174,000 voting stations across Turkey open at 8:00 am (0500 GMT) and close at 5:00 pm, with the results expected during the night.
In the previous 550-seat parliament, 311 seats were controlled by the AKP, 125 by the CHP, 52 by the MHP and 29 by the HDP. Eighteen were controlled by independents and other parties while 15 were left vacant due to deaths and job changes.