Unity leader Andris Piebalgs confirmed to LTV that the anti-graft bureau has informed the party that it will no longer receive state funding.
It's a heavy financial blow to Unity, said Piebalgs.
In addition, the party has been fined €4,000 for administrative violations.
According to the KNAB website, Unity was granted €35,417 over state funds each quarter following the 12th Saeima election.
After the election, KNAB estimated that third parties linked to Unity spent €58,000 on individual campaign initiatives, going over the legally-allowed limit by more than €43,000.
The third party campaigns are reported to have been carried out by 21 individuals helping eight party candidates.
The party was fined shortly after and was close to being stripped of state funding, however Unity contested the KNAB decision. A first instance court upheld the fine, while a second instance court lowered the fine by €300.
The verdict came into force on October 6 however Unity had been contacting KNAB and the court on what the verdict meant in terms of the party continuing to receive public funding.