Citing a Sunday newspaper report, the three leading centre-left and leftist parties said the government “handed out” to friendly media edited recordings of train staff, to bolster a narrative that human error caused the collision that killed 57 people in February 2023.
“There is only one way: a censure motion,” Nikos Androulakis, head of the socialist PASOK party, said in a statement.
The main opposition Syriza party called on Prime Minister Kyriakos Mitsotakis to resign, and the small leftist New Left party said it would support the censure motion.
The Communist KKE party and the nationalist Hellenic Solution party later said they would back the move.
The disaster occurred when a freight train and a passenger train with 350 people aboard, mostly students, collided near a tunnel outside the central city of Larissa shortly before midnight.
The To Vima weekly on Sunday said leaked recordings of train staff on the night of the accident, played by media at the time, had been edited to suggest human error was exclusively to blame.
In particular, one clip that saw extensive use at the time had the station master giving the go-ahead to an unnamed train driver.
To Vima on Sunday said the discussion was with a driver on an earlier train not involved the accident, but his name was purposely removed to create the impression that it was with the driver on one of the trains that collided.
Who carried out the alleged manipulation is unclear, but To Vima suggested that unauthorised persons had improperly acquired access to material that should have been limited to investigators.
Mitsotakis himself drew fire last year after saying “everything” showed that the accident was caused by “human error” even as the investigation got underway.
The government on Sunday dismissed the report as “baseless” and said it welcomed the no-confidence vote in parliament.
“This vulgar attempt will fail,” government spokesman Pavlos Marinakis said in a statement.
The government has an absolute majority of 158 lawmakers in the 300-seat chamber, enough to weather any challenge.
Opposition parties were already furious this past week after a four-month parliament investigation into the accident concluded without assigning blame to senior politicians.
Opposition lawmakers spoke of an attempted cover-up, noting that the parliament investigation, launched in November separately from an ongoing judicial probe, had failed to question key witnesses.
Over 30 railway employees and officials face charges over the disaster, with a trial expected to start in June.
Greece’s 2,552-kilometre (1,585-mile) rail network has for decades been plagued by mismanagement, poor maintenance and obsolete equipment.
Some relatives of the victims have appointed their own experts to the case, arguing that the official investigators wasted time and overlooked vital evidence.
