In an announcement by the KKE central committee, the party expresses its deep grief at the unexpected death of Tzekis, and extends its most heartfelt condolences to the deceased's family.
Tzekis was elected an MP for the first time in 2000 on the KKE ticket in Thessaloniki B' district.
The Greek parliament observed a minute of silence on Monday morning in tribute to Tzekis, whose death was announced to the House by parliament's 2nd vice president Rodoula Zissi, who said that parliament and the Greek society was poorer as of today.
"We lost an eminent Communist, a fighter for the working class' interests," KKE parliamentary spokesman Spyros Halvatzis said.
Labor minister George Koutroumanis said that Tzekis was a consistent fighter and exceptional person.
Ruling PASOK MP Dimitris Papoutsis expressed the party parliamentary committee's deep grief, saying that "we came to know him from his action...he contributed to the popular struggles in a very worthy way".
Main opposition New Democracy (ND) parliamentary group secretary Costas Tassoulas said the party was crushed by Tzekis' sudden death.
Popular Orthodox Rally (LAOS) parliamentary spokesman Adonis Georgiadis said Tzekis had been a "tough ideological rival".
Coalition of the Radical Left (SYRIZA) parliamentary spokesman Dimitris Papadimoulis said that "the entire parliament's grief is mirrored in a stark truth...Angelos Tzekis' sudden death is a big loss for the Greek parliament and Greek society".