The borough council's minority Labour leader Mike Le-surf lodged a complaint after the town's MP revealed that a conversation between residents and a rival Labour MP had been overheard and passed to him.
Local Government Secretary Eric Pickles made the revelation during a debate in the Commons on Monday involving his shadow minister Hilary Benn, who visited Brentwood on Thursday to meet victims of the so-called bedroom tax.
Mr Benn had asked Mr Pickles what he thought about the circumstances of one particular resident who says she has to move out of the borough due to the new policy.
Mr Pickles replied: "I have to say because the Honourable Gentleman mentioned the town hall in the very small room the Labour Party has, everybody heard what he had to say and everyone heard him planning this particular question."
Mr Le-Surf told the Gazette he is furious that someone had been "listening in".
He said: "It seems that Pickles knows more about the Labour group than the effect his cuts are having on Brentwood residents.
"I was shocked to hear Pickles say that our private conversation with residents in the Labour Group room at the town hall was being listened in on and I have demanded answers from the managing director of Brentwood Borough Council."
Mr Pickles said no one had divulged any information to him.
As for Mr Le Surf's complaint, he scoffed: "What a ridiculous and silly thing to do. I remember when Mike was a nice, fresh-faced person. It's such a shame that he has turned all pompous on us."
