The attack took place in Kurunegala on Monday while members of the New Generation were engaged in election work in support of Common Opposition Presidential candidate Maithripala Sirisena.
Police spokesman Senior Superintendent Ajith Rohana said that an investigation into the attack was already underway spearheaded by Assistant Superintendent of Kurunegala with video evidence being looked into.
He said that they have already found evidence to link the government Provincial Council member and are expected to make the relevant arrests of all persons connected to the attack in due course.
Popular vocalist Lakshman Wijesekera, film actress Samanali Fonseka and photographer Udaya Dharmawardena were injured in the attack.
Mohan Raj Madawela has already revealed to the Press that Provincial Council member Namal Indika and a band of his supporters wearing blue T-Shirts to signify the government's Blue Brigade were involved in the attack.