A man was punched to the ground and left unconscious after an argument broke out at a petrol station.

The victim is in hospital with a serious head injury following the incident which took place on the forecourt of the Esso petrol station in Watling Street, Radlett, last night.

Police were called to reports of a dispute at 8.42pm between a man in his 40s and a man who was driving a black Mercedes A180.

The victim was punched in the face before he fell to the ground where he became unconscious. The attacker got back into his car and drove off leaving his victim lying on the floor.

The suspect is described as a white man aged in his 20s with light brown hair and stubble. He was wearing a black t-shirt and jogging bottoms.

Enquiries are ongoing.

Anyone who witnessed what happened or has any information is asked to call 101 quoting crime reference number 41/31433/18.