TRAM inquiry chairman Lord Hardie is under pressure to speed up his investigation after it was revealed the cost of the probe had soared to £3.7 million.
The retired judge was appointed two years ago to head the probe into what went wrong with the Edinburgh trams project, which was completed late and at twice the price for only half the route.
But so far it has held only one brief public hearing and there is no date for it to report.
Figures released by Transport Scotland under Freedom of Information show the inquiry has so far spent £3.7m, including £1.822m on staffing, £716,000 on legal fees, £540,000 on IT costs and £502,000 on accommodation.
City transport leader Lesley Hinds said: “All parties on the council supported the inquiry being set up so we can learn lessons for other capital projects. We have co-operated and made everything available.But it does seem to be taking a long time. It’s two years since it was set up and we don’t appear to be getting anywhere.
“It is concerning that there is still no timetable. Questions need to be asked about why it is taking so much time and costing so much.”
When Lord Hardie was appointed in June 2014, the then First Minister Alex Salmond said the inquiry would be “swift and thorough”.
Senior SNP councillor Steve Cardownie said: “I’m at a loss to see why it is taking so long and what it is focusing on.
“Inquiries are only really useful if they can point the way forward and lessons are learned. Otherwise it’s just an exercise in pinning blame.”
He said he was the only councillor who had voted against the project from the outset.
“I’ve kept all my documents and minutes – I have a huge file. And my memory is fresh on how all these things happened.”
But he said he had not been contacted by the inquiry team.
The inquiry employs 25 staff who are said to be reviewing a massive six million documents.
But Cllr Cardownie said: “I would have thought someone could have weeded through that. I’m not sure what they are concentrating on. It’s unfortunate it’s costing so much public money to look into a scheme that cost the public so much more than it should have.
“The inquiry can only be worthwhile if it produces hard and fast, strong recommendations from which we and other local authorities can learn not to plunder the public purse for schemes which are ill-thought out, ill-judged and not properly prepared.”
A spokeswoman for the inquiry said: “The Scottish Ministers have been clear from the start that the inquiry should be timely and cost effective.
“Substantial progress has been made, including identifying, retrieving and reviewing more than six million documents and the ongoing process of taking extensive statements from witnesses of interest.
“This work is essential to ensure that the inquiry can proceed in an efficient manner in order to produce a comprehensive, fair and balanced report that delivers best value for the public purse.”