By Tom Perry
BEIRUT (Reuters) - Syrian Kurdish groups and their allies will approve a constitution for a new system of government in northern Syria next month, a top Kurdish politician said, defying a Turkish incursion aimed at curbing Kurdish influence in the area.
The new system will be established in parts of the north where Kurdish groups have already carved out autonomous regions since the start of the Syrian conflict in 2011, alarming Turkey which fears the rise of Kurdish influence on its border.
"We have decided to convene a meeting of the founding assembly of the federal system at the start of October, and we will declare our system in northern Syrian," Hadiya Yousef, who chairs the assembly, said in an interview.
"We will not retreat from this project. On the contrary, we will work to implement it," she said.
"The Turkish intervention will not obstruct us."
Kurdish officials say the new system will deepen and widen the existing autonomous administration, allowing for an expansion into areas that have been captured from Islamic State by Kurdish militia and their allies from other ethnic groups.
The plan underscores the Kurds' emergence as a major force in Syria since the onset of its war. While Kurdish officials deny suggestions they aim to establish a Kurdish state, they do not hide their goal of safeguarding their autonomy in a country where they faced systematic discrimination before the conflict.
Their unilateral moves are taking place against a backdrop of international failure to promote a wider peace. Their efforts are opposed by both the Syrian government and its Sunni rebel opponents, but underpinned by one of the most powerful militias in the country, the Kurdish People's Protection Units (YPG).
Turkey views the YPG as an extension of the Kurdistan Workers Party (PKK), which has waged a three-decade insurgency for Kurdish autonomy in southeastern Turkey. But the YPG has also been an important partner for the United States in its campaign against Islamic State in Syria.
Turkey's incursion into Syria has targeted a 100 km (60 mile) stretch of territory between the two main Kurdish-controlled areas of northern Syria, obstructing plans to link up territory known in Kurdish as Rojava.
Syrian rebels backed by Turkey and hostile to the YPG have moved into the area since the incursion began late last month. Turkey aims to both drive Islamic State from the border, and to prevent further Kurdish gains.
Yousef said she expected a city captured by Kurdish-allied forces last month to join the federal system, though the Turkish-backed rebels are also laying claim to it. The city, Manbij, is to the west of the Euphrates River.
"According to our view ... the people of Manbij are eager to join the federal system and accept it," Yousef said. "I believe Manbij will enter the borders of the federal system."
Both the United States and Turkey have demanded the Kurdish YPG militia withdraw from positions west of the Euphrates. The YPG says it has done so. Turkey and its Syrian rebel allies say it has not.
Manbij was captured by the Syrian Democratic Forces alliance, which includes the YPG, in a U.S.-backed operation.
The United States voiced opposition to the federal plans when they were first announced in March.
Yousef said the Kurdish groups and their allies were still seeking to link up the regions, or cantons. "We are working to reach the Afrin canton," she said, referring to a region of northwestern Syria. "We will not retreat from that."
The constitution, known as the social contract, will be approved by a 151-member council chaired by Yousef. Work will then begin on a law for elections to be conducted at the local level, to be followed later by regional elections.
The draft constitution names the city of Qamishli at the Turkish border as the capital of the new federal region, she said.
The Turkish-backed rebels have clashed with Kurdish-allied forces north of Manbij since the Turkish incursion began on Aug. 24. A Turkish-backed Syrian rebel commander told Reuters this week he expected a battle for Manbij soon because the YPG had not withdrawn.
Yousef said: "We will certainly respond to any attack that the Turks mount against our forces."
Kurdish officials say their autonomous system will guarantee the rights of all groups and become a blueprint for the kind of decentralized state needed to end the Syrian war.
Some 30 million Kurds are estimated to live in Iran, Turkey, Iraq and in Syria. Kurdish groups have enjoyed autonomy in northern Iraq since the 1990s.
(Writing by Tom Perry; editing by Giles Elgood)