Both families are seeking a Bill of Criminal Letters
which will allow them to bring charges if approved by the judges.
Lawyers for the family of crash victims Jack and Lorraine Sweeney and their granddaughter Erin McQuade have submitted the Bill for Criminal Letters
- required for a rare private prosecution - to the High Court.
The case will then proceed to the High Court for a hearing to decide whether to issue a bill of criminal letters, meaning permission to pursue the prosecution.
A Crown Office spokesman said: "A bill of criminal letters, to be successful, would require to establish sufficient evidence in law.
But lawyers for the determined family of victims Jack Sweeney, 68, his wife Lorraine, 69, and their granddaughter Erin McQuade, 18, defiantly took their Bill for Criminal Letters
to the High Court of Justiciary in Edinburgh to seek a future trial.
On Wednesday, the Lord Advocate was sent documents representing a Bill For Criminal Letters
, effectively laying down a list of potential charges against 58-year-old Clarke.
Mulholland was yesterday presented with a rarely seen Bill For Criminal Letters
The private prosecution involves the production of a Bill of Criminal Letters.
It is estimated that placing a Bill of Criminal Letters before a High Court judge would cost around PS12,000 - a significant sum to most families but a pittance in terms of the Scottish Legal Aid Board's budget.
Carol applied to the High Court for a Bill of Criminal Letters
, which paved the way for a trial.
Recent history throws up only a tiny handful of decisions on whether or not to grant criminal letters
. As Professor Chalmers tweeted earlier, sanction for a private prosecution has only been granted twice since 1900.
To bring a private prosecution, an individual must apply for a Bill of Criminal Letters
which can be opposed by the Lord Advocate and the alleged offender.