A postal worker whose head was “completely smashed” when he was hit by an unmarked police car is suing British Transport Police for £150,000.

Darren Doolan had to undergo multiple surgeries on his skull when he was knocked off his moped in 2011, and now suffers from impaired vision, memory loss, headaches and disturbed sleep.

Acording to High Court papers, Mr Doolan, 30, of Market Road, Holloway was travelling along Caledonian Road to his job at Mount Pleasant sorting office in Farringdon Road when PC Colm Abbott’s Vauxhall Zafira, travelling “at speed on the wrong side of the road”, collided with him.

In October 2011 PC Abbott pleaded guilty to driving without due care and attention and, in January 2012, admitted full liability for the attack in a letter to Mr Doolan.

Summarising the reports of three medical professionals who treated Mr Doolan after the accident, the writ states: “The Claimant sustained a number of significant injuries... fractures to the frontal area of the skull and the right femur were identified.

“There was a significant head injury associated with the skull fractures. The Claimant’s vision has been affected. He suffers from loss of memory, headaches and disturbed sleep. There is a risk of seizures.

“The femoral fracture has united but the Claimant is left with persistent discomfort in his right hip and thigh.

“Following the accident the Claimant began to experience symptoms of a post-trauimatic stress disorder, including anxiety, flashbacks, avoidance behaviour, poor concentration and mood changes.”

Mr Doolan was studying for his knowledge test to be a taxi driver at the time of the accident, and was unable to complete the qualification.

The court papers describe him as “disabled and handicapped on the open labour market.”

They also state that the appeal for £150,000 is for provisional damages, expressing that a further claim could be made as “there is a chance that at some future time the Claimant will develop a serious deterioration in his condition namely: epilepsy.”

A spokesman for British Transport Police (BTP) said: “BTP have accepted liability for this accident.

“We train all those trusted to drive police vehicles to the highest standard and to drive safely.

“Unfortunately on this occasion the officer involved fell short of the standards expected by BTP and we would like to apologise to Mr Doolan for this.

“Due to the fact that court proceedings are active it would be inappropriate for us to comment any further on this case.”