The driver of the Glasgow bin lorry that struck and killed six people could face prosecution by victims' relatives.
Lawyers for Jacqueline Morton, 51, have asked that an inquiry under way into the December 22 tragedy be halted as they attempt to bring a private prosecution against Harry Clarke, 58.
The move follows a decision by the Crown Office not to bring charges against the city council worker.
A fatal accident inquiry at Glasgow Sheriff Court has heard evidence that Mr Clarke had a history of dizzy spells and fainting which he failed to disclose to the DVLA and on job application forms.
Dorothy Bain QC, acting for Ms Morton's family, requested an adjournment to allow them to look into a private prosecution and the motion was backed by relatives of a second victim, 52-year-old Gillian Ewing.
Erin McQuade, 18, and her grandparents Jack Sweeney, 68, and Lorraine Sweeney, 69, also died in the tragedy.
Their lawyer, Mark Stewart QC, said they reserved the right to prosecute anyone found to carry personal responsibility for the crash.
Relatives of a sixth victim, 29-year-old Stephenie Tait, said they would not be involved in any private prosecution.
Their lawyer Ronald Conway told the inquiry: "Telling lies is not a crime; telling lies to the medical profession is not a crime."
The inquiry, now in its fifth week, will hear from the remaining witnesses before the sheriff makes a decision on Ms Bain's request on Thursday.
Mr Clarke himself was expected to give evidence this week but this has been complicated by the prospect of a private prosecution - described by Solicitor General Lesley Thomson QC, leading the inquiry, as a "rare and exceptional beast".
Witnesses on the day of December's crash reported seeing the lorry driver slumped at the wheel as the vehicle mounted the pavement on Queen Street and careered up the road towards George Square where it crashed into the Millennium Hotel.
Doctors diagnosed Mr Clarke with vaso vagal syndrome, a condition that affects the heart rate and blood pressure.
The inquiry has looked at Mr Clarke's medical history as well as the risk assessments that were in place for a heavy goods vehicle travelling through a busy city centre three days before Christmas.
The Health and Safety Executive (HSE) did not conduct its own investigation as it classes the crash as a road traffic accident - not a work-related incident.
HSE inspector Barry Baker, 50, told the inquiry that the HSE investigated after a member of the public was hit and killed by a reversing refuse truck in 2012 and Glasgow City Council was fined £20,000.
During questioning by Mr Stewart, Mr Baker said the HSE took action as the vehicle was reversing to collect glass waste at the time.
He said it the agency would not have acted in the Holm Street incident if the vehicle had been "driving forward to get from point A to point B".
Mr Stewart said: "I understand you are telling me that if we took the exact same circumstances in Holm Street and simply turned the vehicle around, the HSE stops having an active interest?"
The HSE inspector said: "Yes it does."
The agency was asked by the Crown to provide a report on the council's risk assessment procedures ahead of the inquiry.
It found the local authority had taken a "sensible and informed" approach and appeared to comply with HSE guidelines.
Again under questioning by Mr Stewart, Mr Baker said neither he nor colleagues had visited the council or requested paperwork from them in preparing the report.
The inquiry heard earlier from Ian Buick, who interviewed Mr Clarke when he left a job with First Bus and applied for a position at the council.
Sheriff John Beckett has previously been told there is no record of Mr Clarke's reference on file with the employer.
Former transport manager Mr Buick was shown an email he sent in March 2011 titled "references returned" in which Mr Clarke's name was included.
Mr Buick wrote in the email: "I can confirm that I am satisfied with the content of all the references."
Solicitor General Ms Thomson asked the witness: "Can I suggest that you sent that email just to complete a process?"
Mr Buick said: "No, I checked them. If I've sent an email saying that I checked them, I checked them.
He later told the inquiry: "If I was aware of his (Mr Clarke's) absence record then most definitely he would not have reached the interview stage."