Harmony enjoys election support of 15.2% followed by the Unity Party (14.6%) and 12 the Union of Greens and Farmers favoured by 12.2% of respondents. The nationalist party All for Latvia! lags behind with 5.9%
The remaining political forces will not overcome the 5% barrier.
The poll conducted in April among 947 Latvian citizens has shown almost 19% remains undecided, with the same percentage of non-voters.
The election of eight EP deputies to represent Latvia will take place on May 24. Voters will choose from a total of 170 candidates from 14 political parties and organizations.
Early election at 952 polling stations started on Wednesday when more than 20,000 came to vote. Two more early election days are May 22 and 23.