EC secretary-general Puchong Nutrawong said on Monday that the case had been officially handed to the court for a final decision on complaints relating to the poll.
The EC on March 11 issued a yellow card to Bangkok Governor Sukhumbhand Paribatra for violating election law after his supporters slandered Pheu Thai Party candidate Pol Gen Pongsapat Pongcharoen in three public forums before the gubernatorial election last year.
The yellow card means his victory could be nullified but he would be eligible to contest the election again.
A new election will be held if the court rules in line with the EC's decision.
The EC said MR Sukhumbhand would have to stop performing his duties now the court has accepted the case for deliberation. His deputy Pussadee Tamthai will take charge pending the court's ruling.