A judge-led public inquiry into the Edinburgh Trams project will begin hearing evidence on Tuesday.

Lord Hardie's inquiry aims to establish why the £776m project was delayed and came in over budget.

The Edinburgh Trams inquiry has already reviewed more than six million documents.

Former council leaders Jenny Dawe, Ewan Aitken and Donald Anderson have been called to give evidence at Waverley Gate this week.

The local authority's current transport convener Lesley Hinds is also due to give evidence.

It is expected the inquiry will hear evidence from witnesses over a period of several months.

The inquiry comes as the council debates extending the tram line to Newhaven in the north of the city via Leith Walk.

If approved, the £165m proposal could mean passengers would use the new tramline in 2022.

Preliminary hearings for the Edinburgh Trams inquiry began in 2015.

Lord Hardie, a former lord advocate, said Tuesday marked an important new stage in the process.

He said: "The oral evidence heard at the hearing will be used in conjunction with the wide range of evidence already gathered to inform my final recommendations.

"The Inquiry team has already undertaken a substantial amount of activity including identifying, retrieving and reviewing more than six million documents and securing written statements from a significant number of witnesses.

"The hearing marks another important phase of this work."