Of this, £498M is for phase 1a – the line from Newhaven to Edinburgh Airport.
This section was originally expected to cost £545M and it is hoped the reduction will allow the council to press ahead with the scheme. The remainder of phase 1b is a spur route from Haymarket to Granton.
According to the report to councillors, an £87M price for this work is fixed until March 2009 - the date by which they must decide if phase 1b is affordable.
The project was nearly cancelled after the Scottish elections in May because of opposition from the Scottish National Party administration. It changed its mind after losing a parliamentary vote on the project in June and confirmed the £500M public cash promised by the previous administration.
The savings on phase 1a should now reduce the potential funding gap to £40M– much of which may be raised from developer contributions.
The report projects a construction start in February 2008 and opening of phase 1a in February 2011. Utility works are already underway.