In an open letter to Hackney Mayor Philip Glanville, he said the council’s fortnightly newsletter Hackney Today was making paying for local journalism more difficult.
The government has since announced that it was considering direct action to force the council, along with two other London boroughs, to limit the newsletter to quarterly publication.
He told the Citizen: “I hope Hackney Council agrees with me that the existence of a free press is an indispensable asset to public life in Hackney.
“I believe the best way for the town hall to communicate with the people who live here is by working with papers like the Gazette and the Citizen, not competing with them.”
Keith added: “We do not believe that Hackney Council wants to kill off the local press. I take Mayor Philip Glanville at his word when he said on Twitter that he does not believe Hackney Today seeks to compete commercially with us.
“But whether it seeks to do so or not, and what the mayor believes, is irrelevant – this is the effect.”
Mr Glanville has previously defended the council’s policy, arguing it would lose between £100,000 and £150,000 if it did not sell display advertising for the newsletter.