Zack Polanski has apologised for sharing a social media post condemning the actions of police officers who arrested the suspect in the Golders Green attack.
The Green Party leader had reposted a message on X accusing officers of "repeatedly and violently kicking a mentally ill man in the head when he was already incapacitated by Taser."
The decision to share the post had prompted criticism, including from Metropolitan Police Commissioner Sir Mark Rowley in a letter to the politician on Thursday.
In a statement on Friday, Polanski apologised for "sharing a tweet in haste," adding that he should not have commented on police actions via social media.
"Everyone in leadership has a responsibility for lowering the temperature at a time of such tension," he said.
"Police responses to emergency situations such as these do need later reflection in the right forums, but I accept that social media is not the appropriate channel for doing so," he added.
He added that he had invited Sir Mark to "meet with me to discuss the police response and the wider issues raised in his letter".