Greece’s centre-right prime minister, Kyriakos Mitsotakis, called a May 21 general election Tuesday as his party’s long-standing lead in opinion polls has declined in the aftermath of the country’s worst train disaster. A February 28 collision between a passenger train and a freight train in northern Greece left 57 people dead. The disaster stirred public anger, cutting the conservative New Democracy party’s support by a half-point to 4 points over its left-wing main rival, Syriza, according to opinion polls. .

“The country and its citizens need clear skies … our work continues more boldly and with fewer compromises,” Mitsotakis said during a televised Cabinet meeting. Mitsotakis, 55, the son of the late former prime minister Constantine Mitsotakis, has remained popular throughout his four-year term, which was due to end in July.

 But more recently, his reputation has been dented by allegations of wiretapping by state security services, as well as the government’s failure to protect rail network safety.

 The election he called is not considered early because it is within six months of the end of his mandate. Greece is moving to a proportional representation system that is likely to result in six parties with seats in parliament.

The recent slide in the polls for the prime minister’s party has made a coalition government more likely. But Mitsotakis insisted that New Democracy was seeking outright victory. “Greek men and women, in the elections of May 21, will finally have a choice on whether the country will continue to seek and win the challenge of modernisation,” he said.  “At Syriza, we will seek a government of cooperation, even if we have an outright victory. The country is facing huge challenges and needs the widest possible social consensus,” Alexis Charitsis, a spokesman for the opposition party, told private Antenna television.