Confidential Edinburgh tram file revealed

The Edinburgh tram project dispute has left questions over its final cost and completion date

A confidential document obtained by BBC Scotland shows the economic case for Edinburgh trams remains strong, despite the problems afflicting the scheme.

The revised business case for the new tram line claims it will be profitable and deliver important financial, social and environmental benefits.

The document has been kept secret until now, and is to be published on Friday.

The report's authors believe the economic arguments in favour of pushing ahead with construction are compelling.

That is based on what is called "incremental delivery", opening the line from Edinburgh Airport to St Andrew Square in the first instance, rather than continuing all the way to the city's waterfront as originally planned.

Bus fares

Meanwhile, Edinburgh City Council's transport convener, Gordon Mackenzie, has pledged the capital's bus service will not have to be cut to pay for the trams.

Mr Mackenzie is also adamant that bus fares will not have to be increased to pay for the tramline.

The message here? The shorter line will still make money within the first three or four years and Edinburgh's much-loved bus services will not have to be slashed to pay for it.

That is an upbeat assessment; but this project remains in crisis.

The complicated and bitter dispute with the tram company's contractors means that no-one knows when the tramline will be completed or what the final bill will be.