A driver accused of falling asleep behind the wheel agreed it was the "most viable explanation" for his knocking down and killing champion cyclist Zak Carr, a jury heard yesterday.

A driver accused of falling asleep behind the wheel agreed it was the "most viable explanation" for his knocking down and killing champion cyclist Zak Carr, a jury heard yesterday.

Donald Pearce took the witness stand at Norwich Crown Court, saying he could give no reason why his car drifted off the A11 at up to 60mph and struck Mr Carr in a layby near Wymondham.

Pearce, 49, who runs the Farmhouse pub in Colman Road, Norwich, conceded during cross-examination by prosecutor John Farmer that his driving fell below the standard of a safe and competent driver and that he "did not know" what his defence was.

The jury had heard how Pearce, who denies causing death by dangerous driving, had been heading back from Stansted after an overnight flight when the fatal crash happened at 7.15am on October 17, 2005.

Mr Carr, 30, of Attleborough, one of the top three cyclists in Britain, had been riding to work at Thorpe Marriott and died of his injuries later that day.

Pearce's counsel, Laurence Bruce, asked if he felt tired before setting off from the airport, to which he replied: "I wouldn't get into a car if I didn't feel safe to drive." He added that he did not feel tired during the journey.

He became emotional when asked about the effect the accident had had on him, saying he was devastated and his life had not been the same since.

Mr Farmer asked: "If you are a person who can drive along in a motor car which, after all, is a lethal weapon, and kill someone and just not know how it happened, that in itself is pretty dangerous, isn't it?" Pearce agreed.

He said he did not think he had drifted into a layby but agreed that evidence from the scene revealed he had done.

"Can you offer any justification for a normal and competent driver to drive into a layby like that?" asked Mr Farmer.

"No," said Pearce, agreeing it fell far below what he would expect of a driver.

"And that's how you drove?" said Mr Farmer.

"Must have been," replied Pearce, who also agreed it fell below normal standards for a driver not to notice what was ahead of him and not to stop immediately after hitting someone, as he had done.

Mr Farmer suggested to Pearce that

it looked as if the most viable explanation was he had fallen asleep behind the wheel.

"It does," said Pearce.

"You have admitted the statutory elements of this offence. What is your defence?" asked Mr Farmer.

"I don't know," said Pearce.

"Are you hoping for a perverse verdict - a sympathy vote?" Mr Farmer continued. "This is pretty serious. Are you in fact admitting no defence to this charge against you?"

"No," said Pearce, who confirmed he was not admitting the charged when asked by Mr Bruce.

The court was told Pearce had driven for 26 years, had a clean licence and was experienced at driving long distances.

The jury is expected to retire today.