Support for Prime Minister Petteri Orpo's National Coalition Party rose by more than a percentage point in Yle's latest survey, while the popularity of the opposition Social Democrats declined.
The survey found 20 percent of respondents saying they would vote for the NCP if elections were held now, reflecting a 1.2 percentage point increase compared to last month.
The SDP still held its position leading the other parties in the new survey, but saw support decline by 0.8 percentage points.
The Finns Party, which is the second-largest party in the coalition government, saw a slight decline (0.2% points) in support.
The increase in support for the NCP was particularly strong at the beginning of January, according to Tuomo Turja, research chief at Taloustutkimus, the polling firm that carried out the survey.
He said that while backing for the NCP was weaker in October and November, it increased in December.
"It can be said that support for the National Coalition Party has returned to the level it received during the parliamentary elections," Turja said.
The SDP — the largest opposition party in Finland — saw a similar development, but in the other direction, as it received increased favour in the autumn, which tapered off towards the beginning of the new year.
"It would seem that at least for now, the SDP's biggest increase is behind us," Turja said, adding that once a party receives around 24 to 25 percent of support, typically there is only one direction to go — downwards.
Support for the Finns Party has levelled off at around 15 percent.
According to Turja, the party particularly saw declining favour in Oulu, where discussion about the fate of Oulaskangas Hospital has raised strong emotions.
Changes in backing levels for the opposition Centre, Left Alliance and Greens were minor at the end of last year, according to the survey.
Meanwhile, endorsement for the two other government parties — the Swedish People's Party (SPP) and the Christian Democrats (CD) — has remained around four percent for some time.
According to Turja, even minor changes in support are significant to smaller parties.
"Support for the SPP has picked up a bit. Support for Movement Now increased significantly in November, and it seems that support has returned to its regular level.
EDIT 14:38 The story originally stated the Social Democrats were in second place in the poll. That has now been corrected.