Syrian opposition negotiators in Geneva receive a steady stream of visitors, all bearing the same request: freeze the demand that President Bashar al-Assad resign as a precondition for a peace deal.

With an eighth round of UN-backed peace talks dragging on, the opposition is in a tight spot.

They insist Assad cannot be part of Syria's longterm future but are being pushed to recognise realities on the ground, where the regime has the upper hand.

"Most of the diplomats that have visited the delegation have repeated the same call," an opposition delegate told AFP, requesting anonymity.

"You have to be realistic if you want to solve the conflict," he described diplomats as telling the opposition.

"They want us to freeze the demand that Assad step down, but not abandon it completely."

- New tactic -

Syria's opposition was pressured ahead of the talks to form a united delegation for the first time, which it agreed at talks in Riyadh.

But the unified delegation has reiterated the need for Assad to go as part of the solution to a nearly seven-year war that has killed over 340,000 people.

Western envoys have argued that suspending the Assad demand would embarrass the government into entering substantive negotiations, according to the opposition.

Seven previous rounds of talks have gone nowhere -- and rival sides have not yet met face-to-face.

The current round, which began last week, remains deadlocked.

The government, outraged over the opposition's intransigence on the Assad question, went back to Damascus but has agreed to return to Geneva next week.

Some in the opposition say flexibility on Assad's fate is not a viable option to break the stalemate.

- No leverage -

"There are growing numbers who are pressing for us to pursue this option, but the representatives of the military factions and some of the political representatives are absolutely opposed," an opposition source told AFP.

Among them is Mohammed Alloush, an opposition delegate and leader of the Army of Islam rebel group.

"Our position has consistently been that Assad must go at the beginning of the transitional period," he told AFP.

"If anyone is retreating from that position, they only represent themselves," he added.

According to UN envoy Staffan de Mistura, Assad's future has not yet been discussed.

Last week, he published 12 principles for a future Syria that he said both sides could agree, including that the country "shall be democratic and non-sectarian".

De Mistura wants "to start the conversation from somewhere else, to get us to agree on general principles and then go into details," a second opposition source said.

- Risky move? -

Experts said abandoning a demand as fundamental as Assad's departure would be risky.

"I don't think the opposition... can do that and still maintain any modicum of credibility in the eyes of the millions of Syrians who sacrificed a lot in the fight against the Assad regime," said Randa Slim, from the Middle East Institute.

But the rebels have little leverage after losing chunks of territory to Russian-backed regime forces in recent months.

Traditional opposition allies like the United States, Turkey and Saudi Arabia, also no longer appear wedded to Assad's departure.

"The opposition's allies are getting tired of the conflict in Syria and want it over. The prevailing thinking is that Assad won this round," Slim said.

The rebels are also being pushed by US and European diplomats to incorporate the main Kurdish Democratic Union Party into its ranks.

Syria's Kurds have been a key US ally in the fight against jihadists, but the opposition views them with suspicion in part because they never took up arms against the regime.

Kurdish officials say they have received assurances from American and Russian officials that no peace deal will be reached without them.

They have already been invited to a new peace conference Moscow plans to hold in Sochi in the coming months.

The opposition sees the Sochi meeting as Russia's attempt to bypass the UN process, but the government says it will aid progress towards a deal.

"The conference will open the door to a broad dialogue among all Syrians, while Geneva restricts it to a government delegation and a group of opposition that does not represent anyone," a source close to the government said.

"The Sochi conference will outline the political solution, which will be presented later in Geneva."

Source: AFP