
In the mandatory quorum, all five members must be present to cast votes on campaign-related offence.
But EC member Sodsri Satayatham took a leave of absent because she had to apply for her visa to visit the United States to observe the presidential election preparations scheduled for October 7-to-16.
Sodsri said she could not complete her visa application in time to rush back to cast her vote on the Withoon case.
She said she has suggested for the rescheduling of the vote to today but some of her colleagues already had other engagements.
It remains uncertain whether the ruling could take place before Sodsri's return from abroad, EC secretary general Suthiphon Thaveechaigarn said.
EC member Sumeth Upanisakorn said his colleagues decided to delay the ruling until Sodsri could cast vote.
Withoon has been accused of involving in electoral fraud during his campaigning in Ubon Ratchathani for the December 23 general election. Leaks from the EC-appointed investigative panel indicated no foul play uncovered.
The EC has the option to rule either to endorse the investigative report or to instruct for additional evidence gathering.