A FURTHER £15 million has been added to the cost of Edinburgh's tram project, though it remains on budget and on track for completion by summer 2014, the council has announced.

A progress report due to go before councillors on Thursday hailed "significant progress" since construction work restarted in April 2011 following a fall-out with contractors.

But it dashed hopes that the project would be completed six months early, saying only that "every effort" was being made to improve the existing timescale.

Attempts to claw back some of the investment by leasing some "spare" trams to other networks in Europe also appeared to have floundered, although "all options" are still being explored.

The idea was mooted more than a year ago, and a report last August suggested it would earn the council £2.7m a year.

The tram project was originally due to cost £545m and connect Edinburgh Airport to the city centre and Newhaven on the banks of the Firth via 11.5 miles of track. But a revised budget of £776m for completing a shorter route which terminated in the city centre was agreed last year after a stand-off with contractors.

The progress report by Sue Bruce, City of Edinburgh Council's chief executive, found that nearly half of £34m risk allowance fund had been spent, but the balance should be sufficient to deliver the project.