The Labour peer, whose official title is Lord Ahmed of Rotherham, appeared at Sheffield Magistrates' Court to admit committing the offence on Christmas Day last year.

District Judge Mark Hadfield was told the 51-year-old had sent and received five text messages while driving his gold X-Type Jaguar between junctions 40 and 35 of the southbound M1.

He drove at speeds of about 60mph in the dark and in weather conditions described as damp. Just minutes after replying to the last text, the peer was involved in a devastating crash which saw his car collide with an Audi stranded in the fast lane near junction 35.

The driver of the Audi, Slovakian Martyn Gombar, was killed instantly, while Ahmed, his wife Sakina Bibi, 49, and his mother, who is in her mid-80s, were all injured. An investigation into the accident was launched and the text messages were found when police analysed the mobile phone Ahmed used to make a 999 call from the scene.

David Scutt, prosecuting, told the court that the dangerous driving charge related only to the sending and receiving of texts and was not connected to the accident, which happened later.

The court was told Mr Gombar's Audi hit the central reservation and turned around so it was facing oncoming traffic. He escaped the wreckage but died when he returned to retrieve his mobile phone.

Several other motorists had already swerved to avoid the stricken Audi before Ahmed's car collided with it, with a Mini also crashing close to the scene after taking evasive action.

Mr Scutt said there was "no evidence" that the mobile phone had distracted the peer at the time of the accident.

He said: "On December 25, he was in contact with a journalist. He was driving from Dewsbury to Rotherham on the M1 and received a series of texts which he replied to.

"The texts were of a professional nature and were substantial, not just one or two words. Ahmed was interviewed three times and accepted what the records revealed."

In mitigation, Steve Smith said the peer accepted he had done wrong but stressed the text messages had no bearing on the crash which followed.

The case was adjourned until December 22. It could be dealt with by magistrates who can hand down a maximum of six months in prison. If the case is committed to crown court, the maximum custodial sentence is two years.