"The letter appears more in self-interest than in the state's interest," Leader of Opposition in the Assembly Ajay Singh said in a statement here.
The plant is being built in Sidhi district by Sasan Power Ltd, an Anil Dhirubhai Ambani Group company, which is setting up another power facility in the same district.
The MP Government had written a letter to Prime Minister Manmohan Singh suggesting that the company should be allowed to use excess coal from the mines allotted to Sasan plant for its Chitrangi unit since it is situated close to these mines.
The Leader of Opposition wanted to know when the State Government signed the agreement to allow the use of excess coal meant for the Sasan plant.
The BJP Government should also reveal how many such letters it has written to the Centre, Ajay said.
The content of the letter and its timing raise suspicion about intentions of the Chief Minister, the Congress leader added.