Nair was manhandled by the workers said to be activists of Aranmula Paithruka Grama Karma Samithi (APGKS), a pro-Sangh parivar outfit, when he came to attend a function at a temple in Aranmula, they said.
The MLA's clothes were torn in the incident and he was admitted to the district hospital, police added.
APGKS has been formed to protect and conserve the environment, nature and heritage and it has been on an agitational path against the airport holding that the project would endanger the environment of the area.