Several areas of off-road work between Haymarket and Gogar are running badly behind the original timetable drawn up at the start of the project.
They include work on a viaduct at Haymarket, which had been due for completion by the autumn of 2008, but will now not be finished until the end of July this year.
Elsewhere, work between Roseburn Junction and Balgreen Road – due mostly to be completed by the end of last year – will continue through until the end of 2011.
There will also be delays to work at Carrick Knowe and at Edinburgh Park.
Tram firm TIE today said scheduling timetables, dating from April 2008, were merely "indicative" and now "obsolete".
Critics, however, said the tram company's handling of the project had been "shambolic".
Last week reports suggested that following a recent dispute with its contractor, TIE was forced to pay out an extra 4.5 million for piling work carried out at Russell Road near Murrayfield Stadium.
The new completion dates were provided by TIE in response to a freedom of information request.
John Carson, a former head of maintenance at Network Rail and also a long-standing critic of the trams, said: "This project is out of control.
"TIE's shambolic performance does not guarantee that the dates given (following the freedom of information request] can be met, so expect even more.
"Combining this with the Russell Road announcement, I now think my original estimate of 1 billion looks conservative."
Despite delays to some of the off-street works, TIE has made good progress with work on the stretch of guided busway from Stenhouse to Broomhouse.
Mandy Haeburn-Little, director of customer services and communications for the tram project, said comparing the up-to-date schedule with the original plan was "not a good measure of progress".
She said: "On a construction project of this scale, we would expect there to be changes applied to our timescales.
"This is entirely normal as the programme is under constant review and takes into account a number of criteria including areas of priority, resources required by area and technical difficulty.
"We also need to be able to respond to any issues as these emerge during the course of the work. Some sections of the work have moved ahead of schedule and because of this the start date does not always lead to an implied end date.
"The dispute with the contractor has been in the public domain for some time now and we remain 100 per cent committed to finding a solution and to delivering the trams for the people of Edinburgh."