Changes to Turkey's constitution envisaged by the ruling AK Party could hand President Recep Tayyip Erdogan new powers to draft legislation directly and pick ministers, senior officials said, moves opponents fear could entrench authoritarian rule, according to Reuters.

A cross-party commission charged with drafting a new constitution collapsed last month after the main opposition pulled out over attempts by the AKP, founded by Erdogan more than a decade ago, to change Turkey from a parliamentary to a presidential system.

Erdogan won Turkey's first popular presidential election in August 2014 and has made no secret of his ambition to imbue the largely ceremonial post with more powers. Previous heads of state had been elected by parliament.

The debate over the constitution has profound implications for Turkey, a NATO member state of 79 million people with aspirations to join the European Union. The outcome could change the way Turkey is ruled and redefine issues ranging from Turkish citizenship to the protection of religious freedoms.

Erdogan's supporters say an executive presidency is vital if Turkey is to have the powerful leadership it needs to take a bigger role on the world stage. They reject suggestions it is about the personal ambition of one man.

His opponents say it will consolidate too much power in the hands of a leader, whose grip over the media, the judiciary and police has tightened in recent years. They fear Erdogan's roots in conservative Islamist politics will take Turkey ever further from Western standards on free speech.

Erdogan has urged parliament to take the issue to a referendum, saying he believes Turks will accept a new charter and stronger powers for the head of state. Amid opposition dissent, the AKP is readying its own draft proposals.

"If it emerges that the constitutional commission cannot work, the AKP will begin work on a constitution including the presidential system and will rapidly complete it," said Mustafa Sen, a chief adviser to Prime Minister Ahmet Davutoglu.

"A decision (on the AKP draft) could be reached before the summer ... We are not writing a 10-volume novel. It must not be a text of more than 60-70 articles," Reuters quoted him as saying.

Several other senior AKP officials said the party's proposals, which would need the support of 14 opposition members of parliament to be put to a national vote, were already under discussion.

The plans would allow the president to dissolve parliament, officials familiar with the discussions said. Such a move would also end the president's term and trigger parliamentary and presidential elections to ensure checks and balances, they added, according to Reuters.

Two senior AKP officials involved in the deliberations said the president would be able to issue decrees to enact legislation without consulting parliament.

"The president in our proposal would be more powerful than under the U.S. system," one of the officials said, declining to be identified because the plans have not yet been finalized.

The head of state would also appoint the cabinet as well as senior figures including ambassadors and some members of the judiciary.