A date has been set for the first preliminary hearing of the public inquiry into the Edinburgh Trams project.

It was announced that Lord Hardie will chair the hearing in the capital on August 19 as a call was made for people and organisations who wish to be designated as core participants during the inquiry to come forward.

Core participants will be people and groups who played a significant role in the trams project, have an interest in aspects of the inquiry or who may be subject to criticism during the inquiry.

It was announced last year that the public inquiry had been awarded statutory powers to allow the senior judge to compel witnesses to participate.

The Scottish Government took action after some of those involved in the project refused ''point-blank'' to co-operate, Lord Hardie said.

The core participants will be able to appoint legal representative and may attend for all or large parts of the proceedings.

Lord Hardie said: "At a brief, formal preliminary hearing on August 19, I will announce the details of those persons and organisations who have been designated as core participants.

"These individuals and organisations will have a key role during the inquiry and participate actively in the proceedings by making statements or asking questions, under my guidance.

"The main purpose of the preliminary hearing is to ensure that all procedural matters are agreed before the start of the inquiry hearings, the dates for which I will announce at an appropriate future juncture and in line with the published order of events."

The trams began operating at the end of May last year after six years of disruption and a long-running dispute between Edinburgh City Council and contractors.

The eventual cost of £776 million was more than double the sum earmarked for the project by the previous Labour-led administration.