The family of one of the Glasgow bin lorry crash victims has called for the driver to be prosecuted.
A fatal accident inquiry into the tragedy which killed six people is currently taking place.
It has heard that driver Harry Clarke failed to disclose information about his medical history on several occasions.
He has a history of health issues including fainting and dizziness dating back to the 1970s, including fainting at the wheel of a stationary bus in April 2010.
The Crown Office said in February that no criminal charges would be brought against him.
A Crown Office spokeman said: "It is clear on the evidence at the time that the driver lost control of the bin lorry, resulting in the tragic deaths, he was unconscious and therefore not in control of his actions.
"He did not therefore have the necessary criminal state of mind required for a criminal prosecution. In addition the Crown could not prove that it was foreseeable to the driver that driving on that day would result in a loss of consciousness.
"This still remains the case and all the relevant evidence regarding these points was known to Crown Counsel at the time the decision to take no proceedings was made."
Relatives of Jacqueline Morton, one of the people killed in the December 22 incident, have released a statement to the Sunday Mail newspaper through their lawyer challenging this position.
It says: "We have all along thought that Mr Clarke should face prosecution and this will be part of the submission made to Sheriff Beckett.
"While the evidential position will be determined by Sheriff Beckett, we wish to state that, based on the information given to the families by the Crown to justify their decision not to prosecute at the time, we do not accept that the Crown were in possession of all relevant information when the decision not to prosecute Mr Clarke was announced.
"Submissions to this effect will be made on our behalf in the closing stages of the inquiry.
"We consider that the statement as to the applicable law apparently made by the Crown is simply incorrect. There is no basis in law for the suggestion that a prosecution for causing death by dangerous or careless driving would require to prove that it was foreseeable that the driver would suffer a loss of consciousness on the day of the collision."
The inquiry is due to continue on Monday morning.