The former head of Edinburgh's controversial tram project is leading a bid to take over Scotland's busiest airport, it has emerged.

Richard Jeffrey stood down as the £150,000-a-year chief executive of Tie, the body formerly responsible for managing delivery of the trams, last May.

Mr Jeffrey has now been hired to advise London-based venture capital firm 3i, one of three parties interested in buying from BAA the airport where he was managing director before joining the trams project.

His role has refocussed attention on the decision not to make public the details of his taxpayer-funded Tie payout, despite assurances that this would happen.

The project has been hit by serious delays, seen its original route truncated and run massively over budget.

City of Edinburgh Council has said the details can only be disclosed at a public inquiry due to a confidentiality agreement.

However, Lothians Labour MSP Kezia Dugdale said: "I have repeatedly said it is in the interest of fairness and transparency that taxpayers are told how much of a pay-off Mr Jeffrey received.

"If this man could potentially be helping to run the city's airport, then everything needs to be above board and upfront."

Edinburgh's tram project was costed in 2003 at £375m for three lines, running north, west and south-east. These were later cut to one. The line will now run from the airport to York Place in the city centre at an estimated cost of more than £1 billion.

Edinburgh Airport is valued at between £450million and £600m. It was put up for sale by BAA last year after a ruling by the Competition Commission that demanded it sell either Edinburgh or Glasgow. The final bids are due in next month, with the sale expected to be concluded by the summer.

The airport serves 9.4 million passengers a year, with that figure growing at 6% to 10% annually. In 2010 it unveiled a £42m departure lounge, and last year it was voted Best European Airport.

The sale initially attracted about 50 parties, and Stagecoach chairman Brian Souter has not ruled out joining one of the short-listed bidders.

Arcus Infrastructure Partners, owner of Forth Ports, was another interested potential buyer, as was Edinburgh investment banker Ben Thomson, with whom Mr Jeffrey is reportedly working through his Inverleith Capital firm.

As well as 3i, which has teamed up with M&G Infracapital and pension fund the Universities Superannuation Scheme, the other bidders are thought to include JP Morgan Asset Management and US-based private equity fund Global Infrastructure Partners (GIP).

JP Morgan Asset Management is believed to be being supported in its bid by an unnamed Scottish company.

JP Morgan owns Cairns and Mackay airports in Queensland, Australia, which are run by another former managing director of Edinburgh Airport, Kevin Brown. He resigned in 2011 after a year in the post and is now chief executive officer at North Queensland Airports.

An airport spokesman declined to comment.