The former board director of the Association of Muslim Professionals Nizam Ismail, who resigned abruptly from his position last week, has pulled out as a speaker in the May Day protest at Hong Lim Park.
He said in posts on both his blog and Facebook page that the move was to protest untruths about him allegedly using AMP for political reasons.
"As a personal protest against untruths on my purported political objectives, and to underscore the fact that I am not seeking political mileage arising from my withdrawal from AMP and to speak at the May Day protest, I have, with a heavy heart, decided not to speak at the May Day rally at Hong Lim park," he wrote on Facebook.
Mr Nizam also denied accusations that he is promoting race-based politics, and said that he wants to nurture civil society.
"I have made it clear that my departure was not because of a desire to join any political party, but out of my personal disagreement on the use of funding cuts as a means to curb civil society activism or to discourage critical views," he said.
"I have always been an advocate of a vibrant civil society - which Singapore needs to embrace and nurture, for it to become a resilient society."
Mr Nizam quit in a storm of controversy last week as a board director of the AMP, a Malay-Muslim self help group. He said that his decision to resign from AMP was linked to official pressure, an allegation that both AMP and the Government have rejected.
Describing his week as "trying" he said his withdrawal may disappoint some friends but asked for their understanding "that I am doing so in the broader hope of giving civil society a bigger voice in Singapore".
"This will also allow my family and I to take a step back and have some quiet time on May Day for us to heal and to re-strengthen our bonds."