Police earlier this week arrested Vinod Kumar (34), a local functionary of the CPI(M) and Rajendran (48), another worker, on a complaint of the woman.
She and her husband were allegedly harassed by the duo when she had gone to her husband's firm here to help him with his work on Sunday last.
The duo wanted to know what the couple were doing together on a Sunday. When she said they were a married couple and showed her 'thali', the two refused to accept it, saying anyone can purchase a thali for Rs 50 in the market.
CPI(M) Thiruvananthapuram District Secretary Kadakampally Surendran in a Facebook post today apologised to the woman and her husband, who were harassed by the duo on Sunday last by seeking to know what they were doing together.
The behaviour of the party cadres cannot be accepted. The party firmly believes that "personal freedom" is 'very precious'.
"I apologise on their behalf. We are saddened by their action," he said.