The opposition Finns Party saw a nearly two percentage point (1.9%) boost in support in December, pushing Prime Minister Sanna Marin's Social Democrats out of second place.
Support for the government-leading SDP held nearly steady at 18.8 percent while the Finns Party received 19.3 percent support.
The Finns Party's support increasingly came from women, according to Tuomo Turja, the research director at polling firm Taloustutkimus, which carried out the survey.
"Actually, all of that increase in support came from women," he said, adding that the party particularly attracts support from people who did not vote in the last parliamentary election.
However, it is too early to say how it will play out in April, Turja explained, as there are now fewer undecided voters than in previous elections and the Finns Party may find it difficult to gain more ground.
Despite losing a percentage point of support over the past month, the opposition National Coalition Party led the poll at 23 percent, nearly four points ahead of the Finns Party.
Unlike the parties at the top, support for the Green and the Left Alliance parties was almost unchanged, compared to November's survey, which Turja characterised as interesting.
Meanwhile, the Centre Party, which has seen declining support over the past year, received a nearly two-percentage point increase, but remained at 10.9 percent of support among potential voters.
"There are women and families with children particularly among the new voters, so it is possible that the [Centre-supported] extra child allowance paid out in December strengthened the Centre's support," Turja said.
The Swedish People's Party saw a slight decline, but the support it received is generally in line with long-term polling results.
Support for the Christian Democrats was also low, but there was no major change compared to long-term trends.
Hjallis Harkimo's one-man party Movement Now (at 1.3%) has seen declining support over the past year.
The Yle-sponsored survey was conducted by polling firm Taloustutkimus from 7 December 2022 until 3 January 2023. It queried 2,953 people and had a margin of error of 1.8 percent in either direction.
