Poland holds elections this week that experts say are set to be won by the governing populists, putting the country on a collision course with Ukraine and the European Union.

The latest polls show the Law and Justice party at 32 to 34 percent, a few points ahead of the Civic Coalition led by former EU chief Donald Tusk.

But the ultimate result is likely to hinge on which of the two can build a governing coalition.

The election "is extremely close fought and evenly balanced," Aleks Szczerbiak, a politics professor at the University of Sussex, wrote in a blog.

Dorota Dakowska, a politics professor at Sciences Po Aix in southern France, said it was "the most important election" since the first vote of the
post-communist period in 1989.

"What is at play is the future of democracy in Poland and the future of Poland as a democracy and a country of rule of law," she said.

While Law and Justice is set to get the most votes in the parliamentary elections for the third time in a row, it appears set to fall short of a majority.

The most obvious partner is the far-right Confederation party, which wants Poland to stop aid to Ukraine and has criticized the rights of Ukrainian refugees.

But the opposition's ratings have been going up in the most recent polls and a coalition of three opposition parties may have more chance of forming a government.

Even if they do so, however, they could face hostility from government ally President Andrzej Duda and are unlikely to garner the 60 percent majority of seats required in parliament to overturn presidential vetoes.

Tusk managed to bring together hundreds of thousands of people in the streets of Warsaw this month in an unprecedented show of force by government opponents.

But he has concentrated his campaign in rural areas and small towns where support for the ruling party is still strong, focusing on the state of the economy.

with AFP