Slovak lawmakers approved a change in the constitution on Wednesday which allows the parliament to shorten its term, paving the way for an early election in September.
The current government of Prime Minister Eduard Heger lost a no-confidence vote in December after a former coalition party joined the opposition which claims the cabinet has not done enough to help people with the rising cost of living.
Opinion polls have given the opposition, including the leftist Smer party of former prime minister Robert Fico, a lead over current centre-right government parties.
Fico has taken a critical stance on Slovakia's weapons supplies to neighbouring Ukraine, and his victory could change the NATO country's stance on engagement.
Under the constitutional amendment, parliament will be able to shorten its four-year term if 90 of the 150 lawmakers support such a motion.
A vote can take place once the amendment is published in an official register, which usually happens a day after the bill's approval.
The early elections should take place on Sept. 30 as agreed by parties of the former ruling coalition.
Heger's government is expected to stay on in a caretaker role until the early election.
The early polls will cut the regular four-year parliamentary term by about five months.
(Reporting by Robert Muller, editing by Jan Lopatka and Christina Fincher)
