ATHENS (Reuters) - Greek pensioners took to the streets of the capital on Thursday to protest against a new wave of pension cuts the leftist-led government imposed as part of an austerity drive prescribed by international lenders.

About 3,000 pensioners chanting “Liars!” rallied outside the Labour ministry in central Athens where they burnt government letters outlining the reasons behind the new reductions in their supplementary pensions.

“They (the government) burnt our lives. We are burning their disgraceful letters,” a pensioner said over a loudspeaker.

Protesters later marched to parliament chanting “Bring back the stolen money!”

Prime Minister Alexis Tsipras was first elected 23 months ago promising to end years of austerity imposed by the European Union and International Monetary Fund lenders in exchange for vital bailout loans.

But he was forced to reverse course to keep Greece in the euro zone, signing up to a third bailout in July last year and pursuing deeper cuts and reforms. His coalition government’s popularity ratings have been dropping for months.

Participation in street demonstrations has so far been low but tensions often flare in protests. Pensioners have been particularly hit since Greece signed it first bailout in 2010.

“Our living standard is below zero,” said 74-year old pensioner Yannis Souliotis, one of the protesters.

Private sector workers will stage a 24-hour strike on Dec. 8, the largest labor union said on Wednesday. Public sector unions were to decide later on Thursday if they would join them.

The walkout is aimed at coinciding with a crucial bailout review on unpopular labor reforms. Tsipras wants to conclude the review swiftly to qualify for more debt relief hoping to convince voters that their sacrifices are bearing fruit.