The attack took place at around 6 AM at Kattakada, in the city outskirts, police said.
A video of the incident, which went viral, shows the two attackers pushing the victim, Kumar, riding a bike and attacking him with a weapon as he falls down.
He managed to escape and is undergoing treatment at the Neyattinkara government hospital.
Kumar, an agent of CPI(M) mouthpiece 'Deshabhimani', was distributing copies of the newspaper when he was attacked.
SDPI has denied their involvement in the incident.
More From This Section
On November 17, a march taken out by SDPI was allegedly attacked by some CPI(m) workers at chavara in Kollam district.
Protesting against this, SDPI took out a march to the Secretariat later that night and police used tear gas to disperse them when they turned violent.
Meanwhile, DGP Loknath Behara said patrolling has been intensified and police wold handle such incidents with a firm hand.