A court bid to bring a rare private prosecution against Glasgow bin lorry crash driver Harry Clarke has been rejected by senior judges.

The family of three crash victims took their case for the 59-year-old to be put on trial to the Appeal Court in Edinburgh earlier this year.

The unusual legal move followed a controversial Crown Office decision not to prosecute Mr Clarke, who had blacked out behind the wheel on the day of the fatal crash in December 2014.

Judges Lady Dorrian, Lord Menzies and Lord Drummond Young had been considering the Bill for Criminal Letters since hearing final arguments in the case in October and ruled on Friday the family cannot pursue a private prosecution of Mr Clarke.

The Herald:

The court also rejected a similar plea for a private prosecution of motorist William Payne, lodged by the families of students Mhairi Convy and Laura Stewart, who were knocked down and killed in Glasgow in 2010.

Mr Clarke was driving the bin lorry when it went out of control in Queen Street on December 22 2014, killing six people in total.

Relatives of crash victims Jack and Lorraine Sweeney, aged 68 and 69, and their granddaughter Erin McQuade, 18, brought the private prosecution attempt to court.

Stephenie Tait, 29, Jacqueline Morton, 51, and Gillian Ewing, 52, also died in the collision.

A fatal accident inquiry (FAI) last year heard Mr Clarke lost consciousness at the wheel and he had a history of health issues - including a previous blackout in 2010 when at the wheel of a stationary bus - but had not disclosed his medical background to his employers or the DVLA.

The Herald:

The Crown Office insisted there was insufficient evidence in law to raise criminal proceedings against Mr Clarke but the families of the victims disagreed.

In the separate case, Ms Convy, 18, and Ms Stewart, 20, were walking in Glasgow's North Hanover Street on December 17 2010 when a Range Rover apparently lost control, mounted the kerb and hit them.

An FAI found the crash happened after Mr Payne suffered a ''vasovagal episode'' and temporarily lost consciousness.

He was initially accused of causing the deaths of the students but the charges against him were dropped in November 2013.

The three judges heard detailed arguments in September and October from the families and from the Crown, who did not support either private prosecution bid.

In a brief hearing, judge Lady Dorrian told the court the Bills would be refused in either case.

There was audible sobbing from a member of the public gallery as the decision was given.

During the earlier hearings, which could not be reported at the time, Lord Advocate James Wolffe QC argued there was "not sufficient evidence to support prosecution" in either case.

It is important that prosecutors can take decisions independently - and must be free to take unpopular decisions, he argued.

John Scott QC, representing Mr Clarke, said the prosecution bid wanted to rely on the sheriff's FAI conclusions but that the determination of the sheriff was not admissible in evidence.

The solicitor advocate also said other parties have started considering private proceedings in other cases and to grant this one could "open the floodgates".

Gordon Jackson QC, for Mr Payne, said the Crown had made the correct decision on the evidence.

He argued the whole purpose of FAIs could be undermined by the threat of private prosecutions, with no-one wanting to give evidence over fears they could later face charges.

The sheriff who oversaw the bin lorry FAI ruled the accident might have been prevented if Mr Clarke had "told the truth" about his history of blackouts.

Sheriff John Beckett QC found Mr Clarke "repeatedly lied in order to gain and retain jobs and licences", and "deliberately concealed relevant information from the DVLA".

The families of Mhairi Convy and Laura Stewart expressed their disappointment over the ruling outside the court.

Cate Cairney, aunt of Laura Stewart, said: "The judgment today hasn't surprised us at all. We've been expecting it to be a no decision.

"Since December 17 when Laura and Mhairi were brutally mown down by William Payne, we've all found ourselves locked in a most brutal horror story.

"As average, normal families we expected that justice would take care of itself, that COPFS would do their core job on behalf of the victims and would fight for the truth.

"Having never been exposed to any criminal proceedings before, we were like lambs to the slaughter, eyes filled with tears, broken-hearted and vulnerable to the machine that is COPFS.

"As families who had to identify their daughters, seeing them as no people ever should, we trusted the process and we trusted the law, and this law has fatally let our girls down."

Mhairi's father Alan Convy said: "The Crown Office and Procurator Fiscal Service from the very start nearly six years ago have done everything in their power to protect an early incorrect decision of non-prosecution, to protect the process, to protect their own self-importance and, in doing so, rather than admit they got it wrong, protected William Payne and allowed their non-prosecution of him to give a huge green light to other drivers out there who have black-outs to get on the road and to kill people and walk away.

"We firmly believe that this includes people like Harry Clarke. How many more innocent daughters, parents, brothers, sisters, nieces and nephews have to die before the Crown do the right thing and send out the right message to the public?

"If this ruling is the law, then the law is wrong in our eyes. It needs changed."

The McQuade and Sweeney family sought authority to prosecute Mr Clarke on a charge under sections 1, 1A and 2 of the Road Traffic Act, or for the common law offence of "culpably and recklessly" driving the vehicle and causing the deaths of the pedestrians. A prosecution under the same charges was also sought in the 2010 crash case

In the bin lorry case, the family relied upon Mr Clarke's medical history, his failure to disclose that history in job applications and to the DVLA, his alleged misrepresentations about that history and his actions after the crash.

The complainers in both cases argued there was a sufficiency of evidence which would entitle a conviction to be returned on the charges and that there were special circumstances in each case. They maintained that the Crown has erred in its analysis of the evidence.

But the court held that the Crown had applied the correct test when assessing the legal requirements for a charge of dangerous driving.

In a written decision, Lady Dorrian - the Lord Justice Clerk and Scotland's second-highest judge - said: "It is clear that the Crown correctly considered that the state of knowledge of each respondent on the day in question had to be assessed in the context of all the information known to each of them, including their medical history and any inferences which might reasonably be drawn therefrom. Accordingly, we do not consider that the Crown made an error of law."

She added: "It is quite difficult to conceive of circumstances in which the court would pass a bill where the Lord Advocate had examined and investigated the circumstances of the case, and concluded as a matter of informed judgment that the whole tenor and weight of the evidence did not justify prosecution."

Judges did not consider that the state of knowledge of either motorist "can reasonably be elevated to the degree necessary to be capable of establishing beyond reasonable doubt that on the day in question they drove in the face of an obvious and material danger," she ruled.

"Accordingly, even if we had disagreed with the Crown's assessment, or the weight attributed to individual pieces of evidence, we would be unable to conclude that the decision of the Lord Advocate not to prosecute was so extravagantly wrong as to amount to special circumstances justifying the passing of the bills in either case," Lady Dorrian added.