Having risen to the top of national popularity polls among potential general election voters back in spring, the Social Democratic Party's presence has been waning since the summer.
Secretary General Indrek Saar attributed the trend to massive campaigning by other parties.
"In a few months it will be forgotten and then the parliamentary popularity poll that we are talking about will definitely see changes. Perhaps the coming European Parliament elections will have an even bigger influence on opinion, because they will only be a little over half a year away from the parliamentary elections," Saar told ETV.
Fresh polls place the Center Party as the stable leader at the local and national levels among voters in local elections as well as at the national level among potential general election voters.
IRL has seen its support increase the most in recent months. But the Reform Party and the Social Democrats appear to have been overshadowed by their two other opponents.
The polls showed major support for the Center Party amid a flurry of opening ceremonies for completed city projects, even when money laundering accusations against the party emerged.
The party's political secretary, MP Mailis Reps, said the aggressive pre-election rhetoric has cause alienation on one hand, but on the other hand also mobilized voters to take to the polls.
"Certainly a little bit of friction in the pre-election period brings people to the voting booths," she said.