The Reform Party has sunk to its lowest popularity rating since 2005, and to add insult to injury, its coalition partner, IRL, has recorded its best result since mid-2006.
In this month's TNS Emor survey, only 18 percent of people with a clear political party preference said they would vote for the Reform Party, down 4 percent since the October poll, and down 43 percent from the results of exactly three years ago.
IRL, meanwhile, increased its 20 percent pre-local elections popularity rating to 22 percent to overtake Reform.
The Social Democrats also made gains this month, increasing their support from 20 to 23 percent, while the Center Party remained stable in the polls, clocking up 29 percent support for the third month in a row.
The fresh polls reflect public preferences in would-be parliamentary elections and differ from local election polls, where in addition to Estonian citizens, other long-term residents are quizzed.
Smaller parties failed to meet the 5 percent threshold needed for representation in Parliament, with the Conservative People's Party coming closest with 3 percent.
Only 31 percent of those polled lacked any clear preference, continuing a downward trend. Two months ago, the figure was 43 percent and last month the undecideds were at 36 percent.