Chelmsford Crown Court heard how Anne Milton was tailgating another car at 90mph on the M11 at Littlebury when she lost control and her vehicle flew across the central reservation like a missile.

It struck an oncoming Audi driven by Alexander Palmer, who died instantly.

The court was told at the time of the crash Milton was a disqualified driver and had traces of alcohol and drugs in her body.

Milton 47, of Portland Crescent, Stanmore, Middlesex, pleaded guilty at Chelmsford Crown Court on Friday to causing the death of Alexander Palmer by dangerous driving.

She also admitted charges of driving a Vauxhall Frontera when disqualified and driving without insurance and was banned from driving for ten years.

Carolyn Gardiner, prosecuting, said Milton was given a four-year driving ban in October 2005, for her third offence of driving with excess alcohol.

The crash happened on August 30 last year on the M11 at Littlebury near Saffron Walden, while Milton was driving a Frontera she had bought for £850 four days earlier.

She was returning from Wayland Prison, Norfolk, where she had been to visit her partner, and was accompanied by friend Michael Wall in the front passenger seat.

Witnesses saw the Frontera being driven erratically and aggressively, overtaking one vehicle at 90mph then tailgating another, said Miss Gardiner.

Milton then lost control and catapulted over the central barrier, the Frontera's engine being ejected as it did so.

The vehicle struck an Audi travelling northbound, killing Mr Palmer, who was married with two children and was an executive director of KDC Finance Products in the City of London.

Mr Wall was thrown from the Frontera and was found in the road with his foot severed. He had his leg amputated and later lost his other leg after picking up the MRSA bug in hospital.

Milton was taken to hospital and found to have traces of alcohol, cocaine and diazepam in her blood although she was not over the drink-drive limit. When interviewed at her bedside she denied being the driver and claimed it was her friend who was driving at the time of the crash.

Defence counsel Neil Fitzgibbon said although Milton initially denied being the driver she subsequently faced her responsibility and pleaded guilty.

"She is racked with guilt for what she has done," said Mr Fitzgibbon. "She will have to live with the knowledge she has extinguished someone's life and caused enormous hurt and injury to others."

The court was told Milton – who sat in court in a wheelchair – had shattered her pelvis and most of the bones in her legs and ankles.

Judge Christopher Ball QC told Milton, "You were given a four-year ban in October 2005 and you breached that ban. It was a total and flagrant breach of the order of the court and the law of the land.

"At the time of this tragic incident you had drink and drugs coursing through your body. You were driving fast, erratically and aggressively and lost control of this car with terrible consequences.

"The matter is aggravated by your own despicable attempt to evade responsibility.

"You denied being the driver and blamed another for the driving. I'm not impressed by the argument that you are full of remorse."