Yap Keng Ho, 46, claimed trial to two counts of participating in an assembly without a permit from 2.30pm till 2.40pm.

He is alleged to have committed the offences together with SDP chief Chee Soon Juan, Chee's sister Chee Siok Chin, chairman Gandhi Ambalam and leader of advocacy group SG Human Rights Chia Ti Lik.

Others named in the charges include former opposition candidate Muhammad Jufri Mohd Salim and social activist Seelan Palay.

While the others were released on police bail of $1,000 each pending investigations, Yap was remanded as he was unable to put up the bail.

District Judge Carol Ling did not grant his request for a lower bail but allowed him to post a personal bond for the $1,000 bail.

Yap also said that he was currently involved in another trial for speaking in public without a permit.

He and Chee allegedly committed the offence in the run-up to last year's General Election.

Judge Ling said that the cases would proceed separately.

Yap said that he would engage a lawyer and if none was available, he would represent himself.

He was ordered to attend a conference on Wednesday morning to discuss his on-coming trial.

SDP held the rally to protest rising consumer prices to mark World Consumer Rights Day on Saturday, even after its application had been rejected by the police, who cited security concerns.

Those arrested were among a group of 30 SDP members and supporters who gathered in front of Parliament House with placards.

They also placed food items such as rice, sugar and biscuits on the ground.