KIEV (Reuters) - Thousands of people gathered in Kiev’s main square on Sunday to protest against President Volodymyr Zelenskiy’s deal with Moscow to grant autonomy to Ukraine’s pro-Russian rebel-held east as part of efforts to end a five-year conflict there.

In the first breakthrough toward a possible peace deal in years, envoys from Moscow and Kiev agreed at talks on Tuesday on an election schedule for the Donbass region and on legislation giving it special status. Ukraine also agreed to call back its forces from the current contact line with separatist fighters.

But for many Ukrainians, these measures represent a huge betrayal by Zelenskiy who took power in April after a landslide election win. The war in eastern Ukraine has killed more than 13,000 people since April 2014.

“This is the beginning of the full capitulation of Ukraine,” 53-year-old Roman, who fought in Donbass as a volunteer. He declined to give his surname.

Lawmaker Yana Zinkevych, who belongs to the previous president Petro Poroshenko’s party, “European Solidarity”, was among those who addressed the rally.

“This is Putin’s formula, these are the things that protect Russia’s interests and not ours, we have to fight and prevent its implementation,” Zinkevych told the crowd from a stage in the square.

Last week’s deal opened the way for a resumption of top-level peace talks to end the conflict, which helped send Russia’s ties with the West to post-Cold War lows in 2014.

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Zelenskiy said last week that he would discuss a peace deal for Donbass in upcoming four-way talks with Russia, Germany and France. He said any elections in Donbass would be held only after all Russian troops had left. Russia denies having troops there.

As things stand, Zelenskiy’s party “Servant of the People”, which holds a majority of 251 seats in the Ukrainian parliament, is still short of the 300 votes needed to change the Constitution and give autonomy to Donbass.

“We heard that the parliament must vote for some special status of those territories. We will do our best so that the parliament does not support any special status, any conditions that Russia or Putin imposes on us,” said Inna Sovsun, a lawmaker of opposition Golos (Voice) party.

“The only formula that we are ready to accept is the formula… that was written in our Constitution, the formula, for which thousands of people died, this is the formula of a united sovereign Ukraine”, said Sovsun.