Bashar al-Assad, Syria's president, has indicated that he has no intention of stepping down and insists his departure will not be up for discussion at this week's long-awaited peace talks, which are designed to find a way out of the country's bloody crisis.

Low expectations for the UN-sponsored Geneva II conference, which despite the name will start in Montreux on Wednesday, sank further when Assad reportedly told visiting Russian MPs in Damascus that his future would be decided solely by elections.

"If we wanted to surrender we would have surrendered from the start," the Interfax news agency quoted him as saying. "This issue is not under discussion. Only the Syrian people can decide who should take part in elections."

The president's office later described the Interfax story as inaccurate but did not elaborate. The reported remarks are, however, consistent with previous defiant statements by Assad and other senior Syrian officials.

The Geneva II conference is supposed to discuss the creation of a transitional governing body "by mutual consent" of the government and opposition – language that was first agreed by an conference in Geneva in June 2012 though without the participation of either of the Syrian sides to the conflict.

Assad has insisted throughout that he will not quit, while the opposition says he must go. It remains unclear how that circle can be squared. The UN mediator, Lakhdar Brahimi, plans to chair talks between the Syrian parties in Geneva on Friday – their first face-to-face contact since the uprising began in March 2011. Estimates of the dead range from 100,000 to 136,000. More than 2 million Syrians are now refugees and 9 million are in need of humanitarian aid.

Late on Saturday, the western-backed Syrian Opposition Coalition (SOC) voted by a narrow margin to take part in the conference after coming under heavy pressure from the US and Britain. "We will go to Geneva II without compromising any principles of our revolution," said its president, Ahmed al-Jarba. It would be the "funeral" of the Assad regime, he predicted. The goal was "removing the butcher from power". Still, the SOC faced fierce opposition from within its own ranks: only 58 members of its 120-strong assembly were in favour of attending and 14 were against, with two abstentions and one blank ballot.

Armed groups on the ground in Syria, especially the increasingly prominent Islamist ones, reject any talks with the Assad government. But the head of the western-backed Supreme Military Council, General Salim Idriss, said he supported "a solution that guarantees a political transition of power". Munzer Aqbiq, Jarba's spokesman, said representatives of the Free Syrian Army would form part of the opposition delegation.

Outside the SOC, few opposition supporters believe any progress is possible. "I think Geneva is dead in the water," said a prominent businessman from Homs, now living in exile. "Short of last-minute guarantees from the Americans, how can it work? It's heading for a fiasco."

John Kerry, the US secretary of state, hailed the SOC decision as "a courageous vote in the interests of all the Syrian people who have suffered so horribly under the brutality of the Assad regime and a civil war without end".

William Hague, Britain's foreign secretary, said: "The UN secretary-general has made clear that the aim of the talks is to agree a political transition and an end to the conflict. In contrast to the National Coalition, the Syrian regime has still not agreed to this aim. Any mutually agreed settlement means that Assad can play no role in Syria's future."

Overall, Assad looks in a far stronger position than the rebels who are seeking to overthrow him with the active help of Saudi Arabia and other Gulf states and largely political support from the west. The Syrian president enjoys the firm backing of Russia, which has defended him politically at the UN and supplied him with weapons throughout the crisis. Iran, his principal regional ally, has also been a staunch friend, as has Hezbollah in Lebanon.

Last Friday Syria acceded to Russian requests and offered a local ceasefire in Aleppo and prisoner swaps as a goodwill gesture ahead of Geneva II.

Renewed talk of the Syrian leader's fate prompted a sardonic comment from one witty observer of the crisis. "Bashar al-Assad doesn't want to give up the presidency because it has sentimental value," tweeted @KarlreMarks. "It was left to him by his father."