Center Party Secretary General Priit Toobal said the Social Democrats have come to the aid of their new coalition partner, the Reform Party.
He told uudised.err.ee on Thursday that Social Democratic voters might not approve the party joining a right-led coalition again.
The Reform Party left the impression that it handed over a state in a good condition to new Prime Minister Taavi Rõivas, but in reality the nation is facing new economic turmoil.
Toobal's counterpart at the Social Democrats, Indrek Saar, told Delfi there was only one clear shift in the recent polls, that of the Reform Party winning voters over from IRL, adding that the coalition is more popular than the opposition for the second month in a row.
According to the recent EMOR party popularity poll, the Reform Party has swapped out the Social Democrats as the most popular party, with 29 percent (25 percent a month ago). The Social Democrats lost one percentage point (to 28), the Center Party gained two (to 24 percent) and IRL lost four points (to 15 percent).
The poll asked which party would people vote for in case of general elections, a second poll, mapping European Parliament election preferences, is due on Saturday.