Opposition groups have accused Prime Minister Eduard Heger's government of doing too little to help people cope with soaring energy costs. The debate on their motion started on Thursday afternoon with the final vote set for Dec. 13.

Analysts have said any change in government could affect the EU member's support for neighbouring Ukraine, particularly if there is a victory for the leftist opposition which has criticised providing Kyiv with military equipment.

The government, in power since 2020, lost its majority in September when a junior coalition partner, the libertarian SaS party, left after clashes with the main ruling Ordinary People (OLANO) party, mainly over the handling of the energy crisis.

Heger pointed out in parliament the steps his government took to shield the population from the energy crisis.

"It is necessary to have in place the government which prepared this, and which is capable of making it work," he said.

A government collapse could lead to a period of inertia if Heger stays in office as caretaker with limited powers.

President Zuzana Caputova could appoint a new Cabinet, while parties could seek a new coalition or more likely an early election, which would require 90 votes in the 150-seat parliament.

The no-confidence motion, called by the SaS party and the Hlas party of former Prime Minister Peter Pellegrini, could be close as the opposition controls around 70 votes and still needs six more from various independents to succeed.

Only one of those has clearly said he will vote against the government.

"It's very open, because some of the opposition lawmakers, who have supported the government so far, are ambiguous, while the ruling coalition doesn't have a majority," Radoslav Stefancik, a political analyst at Slovakia's University of Economics, said.

Parliament is due to hold a final vote on the 2023 state budget on Friday. Failure to approve would force the government into a provisional budget that could water down its support for people suffering from high energy bills.

Lawmakers should also vote shortly on windfall taxes on the country's main refinery and gas transit firms to support budget revenue.

Local media reports said a compromise could be found under which some of the independents support both the government and its budget if the coalition agrees to an early election by next September. The next election is currently due in February 2024.

($1 = 0.9526 euro)

(Reporting by Robert Muller in PragueEditing by Andrew Heavens, Jan Lopatka and Matthew Lewis)