A Met Office scientist was knocked off his bike and left with a broken eye socket in an unprovoked attack by a car passenger who was a total stranger.

Car passenger Josh Smith, of Sandringham Road, Newton Abbot, was angry because he was having an argument with his mother and vented his fury on the cyclist who happened to be passing.

Smith’s mother had pulled into a bus stop on the spur road between the Sandygate roundabout and Clyst St Mary and he got out while shouting abuse and waving a bottle.

Met Office radar expert Dr Chris Sloan was cycling home from work and slowed down to avoid the car but was then knocked off his bike by Smith and punched repeatedly in the face and shoulder.

He was left with a broken eye socket which needed a hospital operation to repair and has left him with a small scar on the side of his face.

Smith, aged 22, admitted causing grievous bodily harm and his sentence at Exeter Crown Court was adjourned for a probation report.

Judge David Evans told him that all options, including immediate imprisonment, would be open to him when the case returns to court in three weeks.

Mr Gareth Evans, prosecuting, said Dr Sloan was cycling home at 8.30 pm on June 14 last year when he was attacked.

Smith’s argument with his mother was so violent that she stopped her car near Clyst St Mary and they both got out. He was waving a bottle as Dr Sloan approached them.

Mr Evans said:"Dr Sloan did not say anything or make any comment and simply cycled to within a metre or so when he was compelled to stop because his path was blocked.

"Smith approached and pushed him. He could not prevent himself toppling off his bike and Smith then launched his attack. He had a bottle in his right hand but used his left hand to aim about ten punches.

"Dr Sloan said about five made contact with his face or shoulder. Smith’s mother was screaming at him and Dr Sloan’s impression was that this was what caused him to stop.

"This was a sustained assault in which there was repeated punching when the victim was helpless on the ground."

Smith walked away towards the central reservation and was arrested when police arrived on the scene. He told them he had taken 35 valium and was upset because of an argument with his mother.

He said:"I feel really bad for him. I literally don’t know the guy. He came past and I rammed him straight into a lamp post for no reason."

Mr Lee Bremridge, defending, said he will be urging the judge to suspend the inevitable prison sentence when the case returns to court.

He said Smith is currently on Universal Credit but had started a degree course in the past and has an ambition to be a sound technician.