The 45 year-old man was one of two people assaulted in Hayes on Monday night last week.
Police said it appeared to be an unprovoked attack. As of earlier today, there were no arrests and detectives said that enquiries continue. The map below shows where the crime occurred.
A police statement read: “The attack happened between 10pm and 10.30pm on Monday, 6 March as the two men walked along Atlee Road, near the junction with Ayles Road.
“A group of males got out of a silver car which had driven up Ayles Road and attacked the two men - they then got in the car and drove off.
“One of the victims, 45, was taken to a central London hospital where he remains in a critical condition. The other victim, 28, was not seriously injured.
“Police are appealing for witnesses and information.”
Detective Constable Mark Henry of Hillingdon Police, who leads the investigation, said: "At this early stage it appears to be an unprovoked attack which has left a man critically injured in hospital.
"I am appealing to anyone who was in the area at the time of the incident and, in particular, who saw a silver car being driving erratically in the Ayles Road and Morrison Road area, to contact police."
Anyone with information is asked to contact DC Henry on 020 8246 1455 or call 101. You can also tweet @MetCC. Alternatively, contact Crimestoppers anonymously via 0800 555 111.
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