The coalition gathered around the leftist Social Democratic Party (SDP) is set to win 56 seats in the 151-seat parliament, the exact same number as the Croatian Democratic Union (HDZ) and their allies, an exit poll published on state television showed Sunday.
The poll by the Ipsos Puls agency predicts the results based on surveying a sample of some 29,000 people.
However, it does not take into account votes from abroad, nor voters from ethnic minorities.
The HDZ representatives were skeptical about the survey projections, saying they are usually "not even close to real results."
"The turnout of our voters on the ground was extremely good, and I am certain that the final results will be far better than the surveys," said HDZ Political Secretary Tomislav Suljak.
'This is going to be a long evening'
The newcomer party "Most" is set to win third place and 18 seats, making it the most likely kingmaker in coalition talks.
"We were expecting between 9 and 12 seats - this is amazing," said a Most representative Ivan Lovrinovic. "If this is confirmed by election results, nothing will be politically possible without Most in the next four years."
The party, founded three years ago, has pushed for the reform of a bloated public sector and a better business climate.
The left-wing SDP also responded positively to the projected results, saying they were "open to cooperation" with Most.
"I expected a good result, and this is a good result," SDP vice-president Goran Maras said.
"The people from HDZ who were saying that they will take 20 seats more than us can now see that they were wrong," he added. "This is going to be a long evening,"
Four other parties also crossed the five-percent threshold needed to enter the assembly, according to the survey.
Trouble with refugees
This is the first parliamentary vote since Croatia joined the EU in 2013. One of the main issues during the campaign was the refugee crisis, even overshadowing domestic woes such as the country's economic problems.
"People, you know how important this is," Prime Minister Zoran Milanovic said while casting his vote earlier today. "This is the most important election in the last four years - everything else was just playing around."
The nationalist-rooted HDZ, which steered Croatia to independence from Yugoslavia in 1991, has accused the Milanovic's center-left government of being soft on migrants.
The nationalists demand erecting of barriers to slow down the migrants passing through Croatia along the so-called Balkan route.
The Croatian government's policy of allowing refugees to pass quickly across its territory has drawn heavy criticism from bordering states, notably Hungary. It has also has also added to existing tensions between Croatia and Serbia.
The election commission is expected to announce preliminary results about 10 pm (2100 GMT), according to the Croatian state broadcaster.
dj/rc (Beta, FENA, AFP, Reuters)