The March survey encompassed 873 people interviewed in their place of residence.
The most-supported party remains the opposition Harmony party, backed by 17.7% of those offering an opinion, though the level of support is down 1.3% on the previous month.
Second place is held by the New Conservatives who fell 1.5% and now enjoy the confidence of 8% of voters.
The Greens and Farmers Union (ZZS), now an opposition party, has seen their support grow to 7.6% (+1.7%).
The liberal Development/For! party is next on 6.2% (+0.3%), while New Unity - the party of new Prime Minister Krišjanis Kariņš has seen a rebound after capitalizing somewhat on their central role in government with support down 1.2% to reach 5.3%.
Fourth spot is held by the right of center National Alliance 5% (-1.3%).
Meanwhile populist KPV LV, which started December with a chance of leading a new government, saw its tumbling support increase slightly to 4.1% (+0.6%).
Out of parties that didn't make it into government, the Latvian Regional Alliance enjoys 2.9% support (up 0.5%); the Progressives saw their support decrease slightly to 2.3% (-0.4%) while support for the Latvian Russian Union retreated from the 2% threshold to 1.6%.
Compared to February, ZZS have made a leap from sixth place to third, while New Unity has fallen from third place to fifth.
Generally speaking, no party has seen significant changes in ratings, but support for National Alliance has dwindled to 5%, the lowest point in a year and the party last showed such a poor performance in 2011.
SKDS head Arnis Kaktiņš said that there are no obvious reasons for this, and he ventured to say this may be a simple coincidence and only the ratings of the months to come are to show whether it's a genuine trend for the National Alliance.