Gerald Grange, 51, from Stockton-on-Tees, hit the back of a horse and cart in Cumbria, killing a father and son.

Stuart Nicholson, 44, and his son Connor, aged six, were travelling home from Appleby Horse Fair in June 2003.

The judge at Carlisle Crown Court told Grange that he is likely to face "immediate custody".

He had previously denied the two charges, but changed his plea before the trial was due to commence.

'Immediate custody'

The Crown failed to prove that Grange had been on his mobile phone at the time of the accident.

The court heard that Grange's mobile phone records showed he had made two calls before he dialled 999 to report the accident, but that the calls had not connected.

It is not known if the calls were made before or after the crash.

Chris Stables, prosecuting, said: "The sim card shows that the calls were attempted, but the Crown is prepared to accept a guilty plea on the basis that he was not using his mobile."

Grange, who was given an interim driving ban, was bailed to appear for sentencing in five weeks at Carlisle Crown Court.

Judge John Milford QC said: You have pleaded guilty to two counts of causing death by dangerous driving, and for that there will inevitably be only one sentence, and that is of immediate custody."