A key group within the Syrian opposition National Coalition said Sunday, Oct 13, it would not attend proposed peace talks in Geneva and would quit the Coalition if it participated, according to AFP.

The decision deals a potential blow to international efforts to convene a peace conference in Geneva, which was first proposed for June but has been pushed back multiple times.

The Syrian Red Crescent meanwhile said it had evacuated around 1,500 people from a suburb of the capital Damascus that has been under a regime siege for months.

The president of Syrian National Council, the biggest member of the opposition Coalition, told AFP on Sunday that it was impossible to carry out negotiations given the suffering of people on the ground.

"The Syrian National Council, which is the biggest bloc in the Coalition, has taken the firm decision... not to go to Geneva, under the present circumstances (on the ground)," George Sabra said. “This means that we will not stay in the Coalition if it goes to the peace talks.”

Western nations and Russia have been pushing the regime and the rebels to meet for talks on a negotiated solution to the two and a half year-old conflict, which has killed some 115,000 people.

U.S. Secretary of State John Kerry flew to London on Sunday for talks that will include discussion of the Geneva conference with Lakhdar Brahimi, the UN-Arab League envoy for Syria.

But Sabra said the international community had failed to punish the regime for an August 21 sarin attack on the outskirts of Damascus that reportedly killed hundreds of people.

"The international community has focused on the murder weapon, which is the chemical weapons, and left the murderer unpunished and forgotten the victims," Sabra said. "The regional and international context does not give the impression that Geneva 2 will offer anything to the Syrians."

"We will not participate in a conference that is intended to hide the failure of international politics," he said.