The union members held a protest in front of the power plant to demand the unionisation of their workers and recall of sacked workers.
Armed with placards with various inscriptions condemning the attitude of management towards their workers, the union leaders say they have decided to occupy the power plant until their demands are met.
They also alleged that there is no condition of service at the plant thereby subjecting workers to victimisation and eventual sack.
Some of the workers were brutalised during the protest by some security guards of the plant.
Efforts to speak with the management of Mainstream Energy Solution, owners of the Jebba Hydro Power Plant in Niger state proved abortive.