He is presently, the Member of Parliament from Kollam Lok Sabha constituency.
He was the former minister for Water Resources in the government of Kerala and was responsible for irrigation, ground water development, water supply and sanitation.
He was a Member of the both the houses of the parliament of India (Lok Sabha and Rajya Sabha).
He is known for his public speeches.
An extensively traveled Premachandran had written a book "Oh Iraq" based on his travel experience to Iraq.
He was instrumental in taking up the issue of the safety of Mullaperiyar dam.He initiated a number of innovative steps in drinking water sector.
He began the consultancy wing of Kerala Water Authority called Wascon and mooted the bottled water plant and pipe factory.