Croatia's parliamentary election follows harsh contest between country's top two officials

ZAGREB, Croatia — Croatia's upcoming parliamentary election, set for Wednesday, follows a campaign that was marked by heated exchanges between the country’s two top officials, sparking a political crisis in the Balkan country that belongs to both the European Union and NATO.

The ballot will pit the ruling conservative Croatian Democratic Union (HDZ) led by incumbent Prime Minister Andrej Plenkovic against an alliance of centrist and left-wing parties informally led by populist President Zoran Milanovic and his Social Democratic Party (SDP).

A lot is at stake in the race for Croatia's 151-seat parliament, not just in the country itself but for Europe as it grapples with the instability from Russia's invasion of Ukraine.

If the HDZ stays in power, the country would maintain relative political stability and continue on the pro-Western course in supporting Ukraine in its fight against Russia. A success for SDP could put it on track for victory in the European Parliament elections in June and the presidential election in December. It would shake the HDZ’s long dominance of politics and potentially open space for stronger pro-Russian influence in the country, akin to Hungary and Slovakia.

The HDZ has largely held power since Croatia gained independence from the former Yugoslavia in 1991. The Adriatic Sea nation became the newest member of the European Union in 2013, and joined Europe’s passport-free travel area and the eurozone last year.

The president holds a largely ceremonial role in Croatia, while the prime minister exerts most of the political power.

After Milanovic scheduled the election and announced his surprise bid for prime minister, he began campaigning on behalf of the SDP. But Croatia’s constitutional court judges stepped in, saying the move was unconstitutional.

They said that the president can’t run for prime minister, take part in the upcoming parliamentary election or campaign in favor of any party, unless he first resigns.

Milanovic refused, openly ignoring the top court and continuing to campaign in favor of the left-wing alliance He accused Plenkovic and the HDZ of rampant corruption and “massive theft” of state funds, referring to past and present scandals, some of which had ended up in the courts.

Plenkovic denied the accusations.

The election has played out as the final episode in the long-running rivalry between Plenkovic and Milanovic. Milanovic’s colorful use of insults against his opponents and critics has jarred many but he remains the most popular politician in surveys, seen as speaking openly and using plain words as opposed to the more reserved Plenkovic.

Milanovic has often voiced a pro-Russian stance during the war in Ukraine, opposing the training of Ukrainian soldiers in Croatia as well as sending weapons to Ukraine because, in his view, it only prolongs the war. He called Plenkovic an “ordinary coward” for allegedly preventing him from directly taking part in the election.

“It will be game over for Plenkovic” after Wednesday, Milanovic said, calling on voters to turn out in great numbers "to get rid of Plenkovic and his cartel."

Plenkovic, like Milanovic a former career diplomat, accused his rival of being irresponsible and of "pushing Croatia and the Croatian people into the ‘Russian World.’”

Plenkovic said Milanovic should not hold any public office, describing him as a "political waste that brought only negativity."

Most pre-election polls predict a comfortable HDZ victory, but without enough seats to rule alone. The left-wing opposition may benefit from discontent with high inflation and the general economic malaise in most EU member states. Smaller parties on the right and the left could be key to both the HDZ and SDP in their quest to power.