Mr Ferguson was told on Friday the case was to be dropped

Mick Ferguson, 56, of the West Yorkshire ambulance service was taking a liver to Addenbrooke's Hospital in Cambridgeshire when he was clocked at 104 mph on the A1 near Grantham, Lincolnshire on 16 January.

At Grantham Magistrates' Court on Monday the speeding charge was formally dropped.

Afterwards, the barrister for the CPS, Stephen Lowne, said the rules about speeding ambulances needed to be looked at.

Road users

In a statement he read out said: "The Crown hopes that the procedures for invoking the use of high speed will be reviewed.

"This is so any transgression of the speed limit is both necessary and proportionate.

"That is in the interests of ambulance drivers, other road users and patients."

Mr Lowne told magistrates the CPS was dropping the case against Mr Ferguson because it was "not in the public interest" to pursue it.

But he did say that Mr Ferguson had been driving faster than he needed to.

Operation time

He arrived at Addenbrooke's at 0415 BST after leaving St James's Hospital in Leeds with the transplant donation one hour and 45 minutes earlier.

He did not need to be at the hospital until 0500 BST as the operation was scheduled for 0530 BST.

But the CPS accepted that Mr Ferguson had not been told that delivery of the organ was not as urgent as he believed

Recorded phone calls showed UK Transport for Transplants told West Yorkshire Metropolitan Ambulance Service to treat the delivery as an emergency.

Mr Lowne said Mr Ferguson, who lives in Birkenshaw near Bradford, could have travelled "much slower" but it had been decided he acted in good faith.