A go-getting firm that encouraged a culture of long hours has been found liable for a road accident in which one of its workers was paralysed.

Michael Eyres, who was flung from his van after momentarily falling asleep at the wheel, can now sue the company where he worked as a kitchen fitter for damages expected to exceed £1 million.

His final award will be reduced by 33% because of his own contributory negligence in not wearing a seat belt and knowing he was at risk of falling asleep after working for 19 hours.

But Lord Justice Ward, who gave the ruling of the Court of Appeal today, said Mr Eyres, who was 20 at the time of the accident on the M1 in 2004, was in "in that predicament because his employers had put him there''.

Next to him fast asleep in the van was Craig Atkinson, the 28-year-old managing director of Bradford-based Atkinsons Kitchens and Bedrooms.

Lord Justice Ward said: "Mr Atkinson's saying 'Eating's cheating' and 'You can sleep when you're dead' summed up the company's philosophy."

The judge said the company was "young and successful".

"Its success was no doubt based upon hard work and the clear impression... was that long hours, resulting in good money, were accepted by all to be normal."

He and two other appeal judges overturned a High Court ruling that Mr Eyres was to blame for the accident because he was using a mobile telephone.

On the day of the accident, Mr Eyres had arrived at work at 3.30am after just four and a half hours' sleep when he set off with Mr Atkinson to fit a kitchen in Swindon, Wilts, 111 miles away.

The pair shared the driving and work, which was finished at 2.30pm when Mr Atkinson said they had another job in Sidmouth, Devon, 122 miles away.

They shared Kentucky Fried Chicken on the move and finished the second job at 7pm, when Mr Eyres began the drive home.

He told Mr Atkinson he was "knackered" and asked if they were going to find somewhere to stay the night.

But the judge said he raised no serious objection to travelling home and was "quite content to do the driving".

Mr Atkinson had asked him twice during the journey if he "was all right".

Just 32 miles short of home, Mr Eyres braked suddenly and lost control of his van, which overturned.

His back was broken and he will never walk again.

In the High Court in Leeds last year, Mr Justice Crane said Mr Eyres's driving was "grossly irresponsible and dangerous".

It was not in dispute that his average speed must have been 83 miles an hour on the motorway and he had received and sent text messages while at the wheel.

Mr Eyres told the High Court judge he had not used his mobile phone for more than 20 minutes before the accident.

Lord Justice Ward said that on the balance of probabilities, the cause of the accident was not using a mobile phone but falling asleep.

Damages will be assessed at a later hearing, but the appeal court awarded a £400,000 interim payment.