Mike Ferguson was transporting an organ for transplant

Mike Ferguson, 56, from Bradford, was allegedly clocked driving a marked vehicle with blue flashing lights at 104mph on the A1 in Lincolnshire.

Home Office minister Hazel Blears has told MPs she is in talks with Transport Secretary Alistair Darling about the implications of the decision to prosecute him.

In a Commons written reply, Ms Blears told Liberal Democrat David Laws (Yeovil) she would "consider in the light of this what guidance or clarification of the law might be necessary".

The Government must act very, very quickly because if it doesn't, a lot of lives are going to be lost John Durkin, GMB Union

She added: "I am very aware of the current concerns about the legal position of vehicles which exceed the speed limit whilst transporting human tissue or human organs."

The trial of Mr Ferguson, who is a driver with the West Yorkshire Metropolitan Ambulance Service, has been set for 20 October.

He was making an emergency journey from St James' Hospital in Leeds to Addenbrookes Hospital in Cambridge on 16 January when he was allegedly caught speeding.

Mr Ferguson denies the charge.

Union leaders have warned that lives are at risk unless the government acts to clarify the law.

Speaking after Mr Ferguson's first court appearance GMB branch secretary John Durkin said: "The government must act very, very quickly because if it doesn't, a lot of lives are going to be lost."