The woman said she was called to the police station and humiliated after she filed the gang-rape case.
The Congress on Friday accused the Kerala government and the CPI-M of shielding the men who raped a woman in Thrissur district two years ago.
The 2014 case became public on Thursday when the victim along with her husband and two women activists told her horrid experience to the media in Thiruvananthapuram.
The 34-year-old victim, who hails from Thrissur, alleged that she was raped by a Communist Party of India-Marxist councillor, P.N. Jayanthan, his brother and two others.
Congress legislator Anil Akkara said in the assembly that Kerala, which celebrated its 60th birthday recently, now had to bend its head in shame because of numerous incidents of rape and abuse of women.
"The need of the hour is to keep aside politics and solve the case," he said.
"What's very serious is the victim had in a registered letter to Chief Minister Pinarayi Vijayan in August this year given a complaint and no one knows what happened to it and what follow up action was taken."
Akkara said the CPI-M government was protecting the accused as one of the them was seen in the assembly complex the other day, meeting ministers.
State Minister for Law A.K. Balan said the government was committed to make the accused face the law.
"A new investigation team has been appointed and neither politics nor party affiliations would come before anyone. You (opposition) can also cooperate and provide all the information you have to the government."
But opposition leader Ramesh Chennithala said crimes against women were on the rise in Kerala now.
"Every day a 'Draupadi' is being disrobed in Kerala," he said.
He said while it was true that the incident took place in 2014 when the Congress was in office, the first complaint surfaced only in 2016 after the Left assumed office.
"This case should be handed over to a lady additional director general of police. But you have handed over the probe to an officer who was part of the team before also," said Chennithala, and led the opposition out of the house.