They also took on Finance Minister Pranab Mukherjee for accusing the civil society of trying to undermine democracy and said his statement betrays a "distorted understanding of democracy and arrogance of power".
Two days ahead of the next meeting of the joint drafting committee on Lokpal Bill, its five activist members, including Hazare, sent a letter to Singh alleging that the government seems to be shrinking the scope of the anti-corruption regime.
"Taking the Prime Minister out of the ambit the Lokpal would be a retrograde step," the letter said.
In order to take the Prime Minister out of the purview of the ombudsman, the government will need to amend the Constitution and grant him immunity similar to that enjoyed by the President, they said. They asked if the government is planning to do that and why.
The letter also mentioned that Mukherjee as chair of the Standing Committee on Lokpal in 2001 had himself recommended that Prime Minister should be covered under Lokpal and then Prime Minister Atal Bihari Vajpayee had agreed to that.
Civil society activist Arvind Kejriwal told reporters that the Prime Minister himself had earlier said he will have no problem in being under Lokpal but his ministers are saying otherwise. "Is there a disconnect between them," he asked.