Paul Layden was four times the legal drink drive limit when he was breathalysed after crashing his car on an A47 slip road at Swaffham, a court heard today.

The 46-year-old was being chased by police and driving erratically along the main road between Dereham and Swaffham - even veering towards oncoming traffic at times.

He was recorded driving at speeds of between 20mph and 100mph.

King's Lynn Magistrates' Court heard on Thursday that the driving had initially been spotted by an off duty special constable, who Norfolk Police later confirmed was Lewis Jameson.

Alison Cotterill, prosecuting, said: 'He [Lewis Jameson] was behind Mr Layden's car, a Ford Focus, and he reports that the vehicle was swerving around the carriageway, crossing the lines and driving towards oncoming traffic.'

The special constable made the 999 call and followed Layden throughout the drive on the evening of April 1, constantly relaying information back to the police control room.

At one point, Layden, of Myrtle Avenue, Costessey, failed to brake at the Swaffham BP garage roundabout and went straight across the junction, narrowly missing another vehicle.

He crashed the car into bushes at the A47 Swaffham slip road where he gave a reading of 149 microgrammes of alcohol in 100 millilitres of breath. The legal limit is 35 microgrammes.

During his police interview, Layden said he had been drinking a couple of pints of lager at lunchtime after finding out he had lost his job. He had also had an argument with his then girlfriend earlier.

Mitigating, Ruth Johnson said: 'I cannot disagree with the prolonged bad driving. A 149 breath reading shows a deliberate disregard for others on the roads.

'I am not sure exactly at what time of night this happened, but I know the A47 around Swaffham is a busy road.'

Layden admitted dangerous driving, drink-driving and criminal damage to a property valued under £5,000.

He also admitted another charge of criminal damage to a property valued under £5,000, from March 26.

Magistrates sent the case to crown court for sentencing, at a date to be confirmed.

Chairman of the bench, David Foreman said: 'We will be giving you an interim driving disqualification from now.'