Terming the decision as "unconstitutional and undemocratic", Bhushan said the police acted against the democratic rights of the citizens by denying permission to undertake peaceful protest.
"We will knock the doors of the court," he told reporters.
Bhushan alleged that the democracy under the present government was turning to autocracy and it reminded of Emergency in the 1970s.
After the Hazare team refused to give an undertaking restricting the number of days of protests to three and protestors to 5,000, the police refused to grant permission to them for the indefinite fast demanding a strong Lokpal Bill.