Against the backdrop of the cartoon controversy, Press Council of India Chairman Justice Markandey Katju today said the West Bengal Chief Minister Mamata Banerjee must learn to function in a democratic and more mature manner as she is no more a street fighter.

"I think Mamata Banerjee should have behaved in a more mature manner. She is no more a street fighter, she is the chief minister...the manner in which she has behaved is totally unacceptable," he told a press conference here.

Responding to a question on the arrest of a professor for posting a cartoon of the Trinamool Congress chief on a social networking website, Katju said Banerjee "must learn to be an administrator...now she is no longer in opposition. She must learn some democratic way of functioning."

He said he is a well-wisher of Banerjee and would like her to do well. "But you must act in a democratic manner which she did not...what's wrong if somebody publishes a cartoon. So many cartoons you people have published about me."

At the same time, he said the West Bengal CM was a person of integrity, which was an important aspect.

To a poser on the West Bengal government's decision to ban certain English dailies and high circulation Bengali newspapers from the state-funded and state-aided libraries, he said he had recently raised the issue with Union Minister Sultan Ahmed (Trinamool Congress) and had told him that Banerjee should not take such decisions.

A professor of chemistry of the Jadavpur University was arrested last week along with his neighbour for allegedly posting a cartoon on a popular social networking site involving Banerjee, Railway Minister Mukul Roy and former Railway Minister Dinesh Trivedi.