Slovenian lawmakers on Wednesday debated whether to impeach conservative Prime Minister Janez Jansa, a month before the small Alpine nation takes on the EU's rotating presidency.

For the impeachment vote, expected later Wednesday, to succeed it has to be backed by at least 46 MPs in the 90-seat parliament - a scenario analysts say is unlikely.

If it were to succeed, it would likely see the 62-year-old removed from office and snap elections called.

Four centre-left opposition parties filed the motion in April, accusing Jansa of mismanaging the coronavirus crisis, such as by failing to acquire extra vaccine doses.

They also accuse him of violating press freedom - attacking critical media and stopping the funding of the country's only news agency, STA.

"The prime minister has been acting in an arbitrary, authoritarian, harmful and dangerous way. He's been ridiculing democracy and making fun of its own state and citizens," opposition lawmaker Jani Moderndorfer told parliament.

Jansa, who did not attend the beginning of the impeachment debate, has dismissed the motion as a "pathetic move by the privileged aimed at destabilising the country".

With the nation of two million suffering a relatively high proportion of pandemic deaths compared to other EU countries, the premier's public approval ratings have slumped to their lowest point since he took office in March 2020 following his centre-left predecessor's resignation.

Jansa's centre-right coalition currently controls 45 seats in the 90-seat parliament, with several MPs having left the government camp in recent months.

A fragmented centre-left opposition failed to pass a no-confidence motion in the three-time premier in February.

Slovenia takes on the EU's rotating presidency in July.

Thousands have gathered during protests in central Ljubljana since late last month. They accuse Jansa of undermining democratic institutions and demand new elections.