The Social Democrats ranked as the most popular party again last month, according to an Yle-commissioned survey carried out by pollster Taloustutkimus.
Given the 2.1 percentage point margin of error, the most popular three parties - SDP, Centre and National Coalition Party - are virtually tied.
Taloustutkimus' research director Tuomo Turja said there were no particular changes in support for the top three parties compared to July.
Even though the SDP is holding its top spot, support dropped by nearly a full percentage point since the last time the poll was carried out in July.
Among the three government parties, the NCP enjoyed the most support in August, but approval also dropped by 0.8 percentage points for the conservative party compared to the previous month.
Support for the Centre has remained steady over the past several months, maintaining its position as the country's third-most popular party in August, garnering 17.8 percent support from respondents. Results for the Blue Reform in the August poll, detailed later, were not promising.
The opposition Greens saw another drop in popularity last month. The party had support of 14.9 percent in April but the number of supporters shrank again in August to 12.6 percent.
"The Greens' decline is what catches my attention," the pollster firm's Turja said, noting that the party lost a full percentage point of support compared to July.
The main demographic which has been abandoning the Greens are highly educated women aged between 50-64. The Greens also lost some support from unskilled labourers, according to Turja.
"Very clearly, we can see two distinct groups that have abandoned the party; some unaffiliated voters and those who vote for the Greens or the Left Alliance," he said, noting this month's poll shows that the Left Alliance saw the biggest advance.
Support for the Left Alliance rose by 1.4 percentage points - from 7.7 in July to 9.1 percent in August.
"If we look closely at which groups are increasingly supporting the Left Alliance, it's the same groups that have left the Greens behind," he said, saying that supporters of the two parties share similar values and stances.
Controversy to blame?
Turja said the decline in support for the Greens may be attributable to two controversial incidents involving party members over the summer.
At the end of July the Greens' legal officer Aino Pennanen was removed from a plane before takeoff for refusing to be seated. Pennanen said she was protesting the deportation of a fellow passenger, sharing a video of the incident on social media.
Then days later, at the beginning of August, a photo was published of the Greens' chair Touko Aalto at a nightclub Pride event in Stockholm, Sweden. In the photo a grinning, bare-chested Aalto was shown on the dance floor, appearing to be playfully slapping another man's posterior.
Both incidents received a lot of debate on social media, and reactions to them were mixed.
Populist fracture repercussions?
The Finns Party saw a 0.7 percentage point bump in popularity compared to last month, with 9.4 percent support in August.
The Finns Party's offshoot group the Blue Reform improved slightly in August with 1.6 percent support, a figure below the poll's margin of error..
Turja said the party's poll results were not enough for him to write off the Blue Reform in next year's parliamentary elections, however.
"The Blue Reform's future will rely on what kind of candidates they have and how their campaign proceeds, particularly in Uusimaa [region in southern Finland]," he said, pointing out that a candidate in that region needs around 15,000 votes to get elected.
He said ministers Timo Soini and Jussi Niinistö (former Finns Party members who joined the burgeoning Blue Reform party in the summer of 2017) received a total of 40,000 votes from Uusimaa voters in the last election.
Turja said Soini and Niinistö will likely have less support than during the last election but still thinks they could garner enough votes to be re-elected.
"Their situation is not hopeless but they will definitely need to fight for their existence as a parliamentary party," Turja said.
Support remained steady for the Swedish People's Party, at 4.3 percent.
The survey queried 2,437 people during the period 13 August to 4 September, and has a margin of error of +/- 2.1 percentage points.