BEIRUT (Reuters) - The head of Syria’s main Kurdish political party indicated on Wednesday his group favors attending a Russian-sponsored peace congress later this month, the first time the Kurds would participate in a major diplomatic push to end the war.

Shahoz Hasan said his Democratic Union Party (PYD) would advocate for its decentralized model for Syria, which it says is the only way to end the six-year-old conflict that has made half of Syrians homeless and killed hundreds of thousands.

“We tabled the democratic federal solution in mid-March of 2016, and without it there are no solutions but only rendering the Syrian crisis permanent,” Hasan, PYD co-chair, said in written responses to questions from Reuters.

Although he did not firmly commit to attending the Nov. 18 peace conference in the Russian Black Sea city of Sochi, he said a majority among the PYD and its allies now favored going: “We are discussing it and the majority view is to attend”.

The PYD has emerged as one of the most powerful players in Syria since the eruption of the civil war in 2011.

Its armed affiliate, the YPG, controls swathes of northern Syria where Kurdish-led local administrations have been set up.

They are allied to the United States as the core of the Syrian Defence Forces (SDF) that, with U.S. air support and ground advisers, drove Islamic State from much of northern Syria and captured the militants’ de facto capital Raqqa last month.

The main rebel groups fighting to overthrow President Bashar al-Assad are planning to boycott the Nov. 18 peace congress in Sochi, which Moscow says will focus on a new constitution.

But attendance by the PYD could be important if it yields steps toward rapprochement between the Russian-backed government and the U.S.-backed Kurds, which between them now control most of the country.

KURDS, GOVERNMENT AVOID CLASHES

The Kurds and the government have largely avoided fighting each other during the multi-sided civil war, with both concentrating instead on fighting other enemies such as Islamic State and Arab rebels hostile to both Assad and the YPG.

The PYD says it is not fighting to win independence, but to ensure any post-war constitution gives autonomy to regions. In September, its administrations held the first part of a three-phase election that will conclude in January with the establishment of a parliament.

Syria’s foreign minister said in September that Kurdish autonomy demands were negotiable. But Damascus recently toughened its stance, declaring on Sunday that Raqqa was under SDF “occupation” and the city would only be considered liberated once the Syrian army recovered it.

Hasan said this showed Damascus was “moving away from the democratic solution” and returning to its old stance “that there is no revolutionary movement in Syria and that the pre-2011 Syria can be recreated”.

“This vision is counter to reality and stands against the democratic solution,” said Hasan, who was elected to his post in September, replacing Saleh Muslim.

He added that solving the crisis required a three-year period of political transition. Hasan did not respond to a question of whether the PYD would seek Assad’s removal from office, the core demand of the Syrian opposition.

The YPG has previously said it would have “no problem with the regime” if Kurdish rights were guaranteed.

The invitation to Sochi marks the first time the Syrian Kurds have been asked to attend a major peace conference. The PYD has been left out of diplomacy in line with the wishes of Turkey, which views it as an offshoot of the Kurdistan Workers’ Party that has fought a decades-long insurgency in Turkey.

Hasan said “the broad lines and fundamental elements that guarantee the solution” should be agreed ahead of time, otherwise the congress would amount to “a media carnival”.