The port would adversely affect Kerala's ongoing Vizhinjam International Deepwater Seaport port in Kerala which is 45 KM away from Colachal, Achuthanandan said in a statement.
The BJP-led NDA government has given clearance to Colachel port "with an intention to destroy" the Vizhinjam port, he said.
He wanted the issue to be discussed at the ongoing session of the state assembly.
The Union Cabinet had on July 4 approved the proposal to build a major port at Enayam near Colachel, which was pending for 17 years. The port will entail an investment of about Rs 25,000 crore.