The commission ruled that Mukdawan was guilty of paying supporters to vote for her in the May 14 general election at 500 baht per person, totalling 25,000 baht.
Mukdawan won over Democrat candidate Punsiri Boonyakiat and contributed one MP seat to the Bhumjaithai Party, a coalition member, which won 71 seats nationwide in the general election.
Since Mukdawan has already been sworn in as an MP, the EC has ordered her to stop all her duties until the Supreme Court pronounces its verdict on her case. Normally, red-carded individuals are banned from politics for 10 years, the source added.
The election watchdog also ordered Mukdawan to pay for the by-election to elect a new MP in her place.
The Democrat Party dominated the southern province in last year's election, winning in six out of 10 constituencies of Nakhon Si Thammarat. Bhumjaithai won two seats, while Palang Pracharat and United Thai Nation parties won one MP seat apiece.
Mukdawan is the first MP to be red-carded by the EC in the 2023 election. The EC previously said it received complaints in 71 constituencies but did not have enough time to investigate all the cases before the swearing-in of MPs, which must take place 60 days after an election.
The EC however has one year, or until May 2024, to investigate the complaints and submit its ruling on those suspected of breaking election laws to the court.