Turkey's ruling AK Party has proposed amending a text on constitutional reform for a referendum this month in order to avert legal challenges to the status of President Abdullah Gul.

Turkish voters are predicted to give an endorsement to the constitutional amendments on 21 October that propose the people gain the power to elect the president, and not parliament as has previously been the case.

President Gul was elected by parliament in August for a 7-year term.

If, as widely expected, voters back the reforms in the referendum, some legal experts have commented that he would have to resign and enter an election race for the post in a popular vote.

An AK Party official said the party would scrap an article in the referendum text that stipulates Turkey's 11th president must be elected by voters. Gul is Turkey's 11th head of state. All future presidents after Gul will then be elected by popular vote.

The AK Party formally submitted its proposal to parliament after consulations with opposition parties. It shrugged off a call from the main opposition Republican People's Party (CHP) to cancel the referendum.

Parliament is expected to approve the revised text in good time before the referendum, AK Party officials said. The issue has threatened fresh political upheaval in Turkey, a European Union candidate nation with a fast-growing economy.

Prime Minister Tayyip Erdogan's government initially proposed the reforms after Turkey's powerful secular elite, including army generals and judges, successfully blocked parliament's first attempt to elect Gul as president in May.

Erdogan also called a snap parliamentary election in July which the AK Party won decisively, allowing the assembly to elect Gul in August under the old constitutional rules.

The secularists dislike Gul's Islamist past and his wife's Muslim headscarf and fear he will try to erode the separation of state and religion, claims both Gul and Erdogan strongly reject.

The amendments to be submitted to voters in the referendum would also cut the president's term to five years, renewable by another five, and parliament's term to four from five years. Now, the president can only serve a single 7-year term.