Thousands of workers will join a nationwide strike on Wednesday in protest over Greece's deadliest train disaster that killed 57 people, and mass demonstrations are expected to culminate outside parliament in Athens.
The crash on February 28 has stirred public outrage over the crumbling state of the Greek rail network, and striking workers say years of neglect, underinvestment and understaffing - a legacy of Greece's decade-long debt crisis - are to blame.
Many of the around 350 people aboard an intercity passenger train that collided head-on with a freight train while travelling on the same track were university students heading to the northern city of Thessaloniki from Athens after a long public holiday weekend.
The disaster has sparked protests across Greece with more than 10,000 rallying in Athens on Sunday, releasing hundreds of black balloons into the sky.
Rail workers have staged rolling, 24-hour strikes since Thursday, bringing the network to a halt. They say their demands for improvement in safety protocols have gone unheard for years.
Wednesday's strike, to be joined by various public sector workers, is expected to disrupt metro, tram and bus servives, and ferries will remain docked in ports as seamen join the walkout.
"We will impose safe railways so that no one will ever experience the tragic accident at Tempi ever again," the main railway workers union said in a statement.
"We have an obligation towards our fellow humans and our colleagues who were lost in the tragic accident."
ADEY, the umbrella union representing hundreds of thousands of public sector workers, also called for a day-long strike and protest over the "murderous crime".
Students and teacher groups have said they will join the rallies.
Greece sold its state-owned railway operator, now called Hellenic Train, under its international bailout program in 2017 to Italy's state-owned Ferrovie dello Stato Italiane.
The government, whose term expires this summer, has blamed human error for the crash but Prime Minister Kyriakos Mitsotakis appeared to accept some of the criticism, acknowledging decades of neglect could have contributed to the disaster.