The inquiry into Edinburgh’s tram fiasco has written to all those who served as councillors at any stage during the project, inviting them to submit evidence.
The probe, led by former Lord Advocate Lord Hardie, was set up to establish what went wrong with the £776 million scheme.
But earlier this year, the Evening News revealed most of the key players, including top councillors, had yet to be contacted by the inquiry.
Now all councillors from the time of the project are being sent letters and questionnaires - and depending on the significance of what they have to say they could be asked to appear before the inquiry at a public hearing.
Former Labour councillor Donald Anderson, who was council leader from 1999 until 2006, welcomed the fact he had now been approached by the inquiry team.
He was in charge when the tram project first secured funding from the Scottish Government, with the outline business case agreed and the arms-length company TIE set up to run the project. The procurement process was also begun during his time in office, although the contract was not signed until the year after he left office.
And Mr Anderson uniquely has experience on both sides of the controversial project because, after leaving the council, he joined public affairs firm PPS and acted as an adviser to tram contractors Bilfinger-Berger and Siemens.
He said: “It is as former council leader they have contacted me and I’ve always made it clear I’m more than happy to co-operate – in fact I’m enthusiastic about doing so.
“I’m as impatient as anyone else to find out where the problems arose and have them publicised as much as possible to make sure something like this doesn’t happen again.
“I was leader when the tram project was initially commissioned and it’s quite right I should be called and held to account.”
Senior SNP councillor Steve Cardownie also said he would welcome the opportunity to give evidence.
He said: “I will go and tell them what I know. I voted against the business case for the trams. I’m more than happy to go and say what I think about it all.”
It is understood the questionnaires sent to councillors vary slightly according to their role and involvement in the project.
A spokeswoman for the inquiry said: “Communications with those involved in and affected by the trams project is an ongoing process. This includes all City of Edinburgh councillors who were elected and have served across the period of the Edinburgh Trams project.
“The co-operation of the City of Edinburgh Council and other core participants will be an essential part of the Inquiry’s deliberations if it is to provide a truly comprehensive account of the reasons behind the failure of the original project to be delivered on time and to budget and scope.”