The Yle-commissioned Taloustutkimus poll found that 57 percent prefer Urpilainen, while only a quarter backs Rinne.
However, among all poll respondents, independent of party affiliation, the two candidates get equal support. One third of those polled did not disclose their preference. The poll carries a 7 percent margin of error.
While Urpilainen was happy for the support from SDP ranks, she noted that in the end it will be representatives to the party convention in May that choose the chair, and not the voters.