Estonians were voting on Sunday for a new parliament in an election that could strengthen far-right nationalists, who have campaigned against further arms deliveries to Ukraine.
Prime Minister Kaja Kallas's centre-right Reform Party is predicted to win by the opinion polls, but will likely have to form a coalition to hang on to power.
The party is expected to garner 24 percent to 30 percent of votes, according to final polls during the week. The far-right EKRE was predicted to take second place with 14-25 percent.
The Centre Party was on 16-19 percent and Estonia 200 between nine and 15 percent.
"Those who don't vote for EKRE will not be rid of the Reform (party)", EKRE leader Martin Helme wrote on Facebook on Sunday.
Former prime minister and Reform Party member Siim Kallas warned of a splintered vote.
"The more the result is muddled and split, the more the government will be muddled, the more the ruling coalition will be weak," he posted on Facebook.
Estonia, a country of 1.3 million people bordering Russia, has a unicameral parliament with 101 seats, all of them at stake in the election.
The Baltic state, a member of the EU and NATO, has led international calls over the past year for more military aid to help Ukraine fight off Russia's invasion.
Estonia's military assistance to Ukraine amounts to more than one percent of GDP -- the biggest contribution of any country relative to the size of its economy.
"It's obvious that what is happening in Ukraine is very important for Estonia as well" 35-year-old engineer Juhan Ressar told AFP at a polling station the capital Tallinn.
"Maybe people ... have forgotten the importance of independence," he said.
Reform's Kallas told AFP in a recent interview, "We support an open, friendly, Western-minded, European, smart country.
"My biggest competitor thinks that we shouldn't help Ukraine, we shouldn't support Ukraine, we should only look for our self-interest," she said.
According to EKRE's Helme, Estonia should not be "further escalating tensions" with Moscow.
EKRE has campaigned against additional military aid to Kyiv, and called for a halt in Ukrainian refugee arrivals and for lower immigration rates to protect local workers.
At the same time, the cost of living crisis has spiralled in Estonia, with one of the EU's highest inflation rates -- 18.6 percent in January over 12 months earlier.
For 62-year-old pensioner Pjotr Mahhonin, only EKRE "represents the Estonian people".
He accused the prime minister of being more interested in "another country", meaning Ukraine.
Like many Estonians, he said he feared war. "We have a big neighbour, Russia, and it's very dangerous.
"If war starts, we are the country on the frontline," Mahhonin said.
The Centre Party, which is traditionally popular with Estonia's large Russian-speaking minority, has supported government policy on Ukraine and on Russia.
This has put off some Russian-speaking voters, and rates of abstention among the minority, around a quarter of the population, could be high.
Reform is a centre-right liberal party that appeals to business owners and young professionals.
It has promised to raise military spending to at least three percent of GDP, ease taxes on business and wants to pass a law approving same-sex civil partnerships.
The Centre Party is centre-left, and is promising more investment in infrastructure and affordable housing.
According to political analysts, a coalition between Reform, Estonia 200 and the Social Democrats is possible, as is one between Reform, Centre and Isamaa.
However, EKRE's chances of fronting a coalition are projected as modest.
The polls close at 8:00 pm (1800 GMT), with first results expected early Monday.
More than 47 percent of voters had already cast their ballot by post or online, according to the electoral commission.
