As parties clamour to have the ban on political activities lifted, Democrat leader Abhisit Vejjajiva said Thursday it would not be appropriate ahead of this month's royal cremation ceremony for the late King Bhumibol Adulyadej.
He said parties could engage in preparatory work, such as updating their membership databases, without convening meetings, as this would not violate the ban.
Mr Abhisit also urged the Election Commission (EC) to draft regulations about party membership in line with the new law.
"The EC can get the regulations ready and spare the public a debate on political issues this month. When October passes, things can proceed smoothly," he said.
Meanwhile, Deputy Prime Minister Wissanu Krea-ngam said parties can engage in election campaigns after a royal decree announcing the elections has been published. This would fall outside the years-long ban on political activities, he said.
Prime Minister Prayut Chan-o-cha said on Tuesday the poll will be held in November 2018, with a date to be specified in June.
CDC chairman Meechai Ruchupan lashed out at the EC Thursday for speculating the election could be delayed if lawmakers reject any of the four organic laws that must be passed first.
Two of the laws, on senators and MPs, are still being drafted.