The poll gives Harmony support from 21% of those canvassed, followed by the Greens and Farmers Union (ZZS) of Prime Minister Maris Kucinskis on 10.5%, and the nationalist National Alliance on 6.9%.
The only other party to make it over the 5% threshold necessary to win seats in Saeima is Kam Pieder Valsts? (Who own the state?), the party of actor-turned-renegade MP Artuss Kaimins on 6.2%.
Still below the 5% threshold is the Vienotiba (Unity) party which had hoped to attract 10% support by the start of 2017 after internal strife destroyed its once dominant position.
Two other parties currently represented in Saeima also attracted little backing in the poll with Latvia's Regional Alliance on 3.8% and Latvia From The Heart on 1.9%.
However, it should also be noted that a large proportion of voters declared themselves undecided (27%) while a further 15% said they were so disillusioned with the political scene they had no intention of participating in local government elections that will take place on June 3.
The figures saw Harmony's support climb from 17.9% to 21% from December to January while ZZS' support headed in the opposite direction, declining from 12.5% to 10.5%.
The news is likely to provide a boost to Riga mayor Nils Usakovs who is seeking to defend his important position on behalf of Harmony.