The Sh200 billion coal fired power plant is being forced on Lamu people, Wiper leader Kalonzo Musyoka said.
Mr Musyoka said the plant had hazardous effects on the environment and human health.
Speaking at a rally in Kizingitini Island in Lamu East during his tour of the area, the Nasa co-principal lauded Wiper deputy party leader and county woman representative Shakila Abdalla for opposing the project.
Mr Musyoka said Lamu people should rise up and denounce the project.
He said a similar project was rejected in Kitui for the same reasons despite the area being rich in coal deposits.
Ms Abdalla said she will not be deterred in her decision to oppose the coal plant.
She said certain individuals “have been pocketed” to accept the coal project.