A drugged up delivery driver who fell asleep at the wheel and killed a charity fundraiser has been jailed for eight years.

Daniel Butler had taken a cocktail of drugs and was fatigued through lack of sleep when he smashed head-on into a car driven by pensioner Suzanne Maclachlan.

The 27-year-old father told a psychiatrist he was taking amphetamine to keep him “sharp” and using cocaine because he enjoyed it.

“There is the deliberate conduct,” said Judge Adele Williams.

The judge told Butler: “I remind myself you did not set out that day to kill anyone. But your driving was grossly irresponsible.

“This was a persistent, prolonged and deliberate course of very bad driving – deliberate because you drove while under the influence of a large amount of drugs. You were also suffering from fatigue.”

The crash happened on the A228 Malling Road in Mereworth on the afternoon of August 20 last year.

Other drivers had been concerned about Butler’s manner of driving before the fatal collision.

Jonathan Lawrence phoned the police after he saw the white Ford Transit van driving close to the car in front and drifting across the road.

At the Hop Farm roundabout the van veered to the left and hit the kerb, causing a cloud of dust and dirt.

Another car was forced to swerve out of Butler’s way. Because of the way he was driving, Shaun Lavis and his partner Vicki Savage, in their BMW, formed the impression he was drunk.

There was a near miss with a Mini before Butler crossed the centre of the single carriageway and hurtled into 67-year-old Mrs Maclachlan’s Peugeot 206.

“Mrs Maclachlan had no opportunity to avoid the collision as the van hit her vehicle head on,” prosecutor Simon Taylor told Maidstone Crown Court on Friday.

“At the time, the van was at least halfway onto the wrong side of the carriageway. Her vehicle spun upon impact.”

The victim, from Wateringbury, was flown to King’s College Hospital in London by air ambulance. She died shortly afterwards from a cardiac arrest.

Butler, of Silverweed Road, Chatham, told paramedics he did not feel he was passing out before the collision. He was not wearing a seatbelt.

He was given a breath test at the scene and it showed a zero rating.

When asked for a second sample to eliminate errors, he became agitated and refused. He told an officer: “F------ right I’m not doing it again. F--- off.”

Mr Taylor said Butler walked to an ambulance, laid on a bed and fell asleep. He also slept in hospital.

After being arrested for causing death by dangerous driving, he replied: “I think I fell asleep at the wheel. I was driving along when I looked up and she was just there.”

A blood sample revealed 22 micrograms of cocaine per litre of blood.

The legal limit is 10; 1,000 micrograms of amphetamine per litre of blood. The legal limit is 250; 259 micrograms of benzoylecgonine. The legal limit is 50.

“The concentration of amphetamine is very high and in the toxic range of the drug associated with fatalities,” said Mr Taylor.

“The concentrations of cocaine and amphetamine in the sample suggest the recent use of drugs, within six to 12 hours of the sample being taken.”

When interviewed, Butler said he had driven from Goudhurst and was delivering Hermes parcels. He said he believed he lost control of the van because of a mechanical fault, but none were found.

About two hours before the crash he had contacted his manager and told him the van was “crabbing” and the back wheels were driving it.

The manager told him to pull over and stop driving if it was not safe. Butler replied he would keep driving and see how it went.

“This was a persistent, prolonged and deliberate course of very bad driving.” Judge Adele Williams

Mr Taylor said Butler’s phone was examined and found to have been in “near constant use” day and night over the four days up to the collision.

A tracker on his van showed excessive use of the vehicle out of work hours.

The longest period of inactivity for the van or phone over the four days was a total of less than eight hours.

“Illegal drugs must have impaired his ability to drive,” said Mr Taylor. “He had little or no rest on the day of the collision.”

He had one previous conviction for harassment in 2011.

He was given a caution in 2016 for possessing amphetamine.

Butler, who admitted the offence, will be banned from driving for seven years when released from the sentence.

He will have to take an extended test before being allowed back on the road.

Ken Maclachan, 62,and his wife of 41 years moved to Wateringbury about 10 years ago.

Zumba fan Mrs Maclachan fought a three-year battle with lung cancer.

She raised thousands of pounds for the Roy Castle Lung Cancer Foundation and the Samantha Dickson Brain Tumour Trust.