LAWYERS representing families of two friends killed in a tragic car accident have blasted prosecutors for their handling of the case.

Lawyers at Digby Brown have criticised the Crown Office and Procurator Fiscal Service (COPFS) for delays in the investigation into the deaths of Mhairi Convy and Laura Stewart.

The two friends were shopping in Glasgow's city centre in December 2010 when they were struck by a car which had mounted the pavement on North Hanover Street.

William Payne, the driver of the vehicle, had suffered six blackouts in three years prior to the crash and did not inform the DVLA of his health problems.

It was revealed this week he will not face prosecution after the Crown Office said they could prove criminal negligence on his behalf.

Now Fraser Simpson, partner at the law firm has slammed the "spineless" prosecutors and said: "The harsh reality is that the immense pain and suffering two families have undergone over the last four years has been aggravated by what they regard as a lack of rigour and competence on the part of the Crown Office and Procurator Fiscal Service."

Mr Simpson said the decision not to prosecute, and the fact it took four years to make, was "hard to understand or accept" and blasted the COPFS for making the decision public before discussing it with the families.

He added: "The inquiry, which the families did not call for, took place at huge cost to [them], both emotional and financial.

"While the comfort of a criminal prosecution may now be denied to them, the families will consider what further legal remedy is available to at least help recover from the Crown some of that cost."

A Crown Office spokesman said: "We can well understand the anguish of the families over the tragic deaths of their loved ones. The Crown, after an extensive investigation and review of all the evidence including the evidence led at the FAI, was unable to raise criminal proceedings as there is insufficient evidence in law.

"This was not a discretionary decision. It is right that this case deserved the most thorough consideration and this process takes time to ensure that all avenues of enquiry are thoroughly exhausted. This was explained to the families this week."