A 56-year-old man has been charged with attempted murder after a policeman was stabbed in the head.
Muhammed Rodwan, of Villiers Close, Luton, is also charged with possession of an offensive weapon after the attack in Leyton, east London, at around midnight on Thursday.
Rodwan will appear at Thames Magistrates’ Court on Friday morning, the Metropolitan Police said.
The officer, 28, remains in hospital in a serious but stable condition.
He managed to taser his attacker despite being brutally injured in the “sudden and brutal” assault which lasted just seconds.
The attack happened after the patrol officer tried to stop a van suspected of having no insurance.
The officer, who has around a decade of police experience, was treated by colleagues and paramedics in Leyton High Road as his uniform lay next to him on the ground.
Witness Muhammad Faisal, 31, said: “We saw someone lying on the road. Next to him was his police uniform.
“They were providing him assistance to his head. We didn’t see the wound, but we saw a lot of blood.”
The attack prompted outrage from policing leaders and politicians.
Metropolitan Police Federation chairman Ken Marsh said: “Police officers across London are out there every day at risk protecting the public – and sadly, yet again, a Metropolitan Police officer has suffered a severe injury on duty.”
He added: “Enough is enough. Police officers should be going home at the end of their shifts. Not to hospital.”
Home Secretary Priti Patel tweeted: “Absolutely horrified by the shocking stabbing of one of our brave police officers in Leyton overnight.
“His courage in the face of danger shows how police put their lives on the line to protect us every day. I wish the officer a full recovery & my thoughts are with him.”
London Mayor Sadiq Khan said it was a “sickening attack”.