The publication today of Audit Scotland's Report on both Edinburgh Trams and Earl (Edinburgh Airport Rail Link), while making excellent reading for those of us who advocate the urgent implementation of Edinburgh's tram plans, raises questions about Earl which clearly need to be addressed.

Of fundamental importance is the fact that the report clearly separates out the two schemes and deals with them as separate issues. It is essential that they are considered thus, and are not treated as one issue by politicians of any party. To insist on linking the two in parliament could result in both projects being lost, which would be a huge injustice to Edinburgh.

The arguments for Earl are completely different to those for Edinburgh's trams, and there are many of us who have serious doubts about the value of Earl. The funds saved on Earl could be used to far greater advantage on other rail projects, including an expanded tram network along the lines suggested by the SNP's own Professor Christopher Harvie MSP.

It is essential that the SNP, with all party support, takes immediate steps to implement Edinburgh's tram scheme, while taking the opportunity to put on the back burner for the meantime the Earl project. Michael Marwick, Dundas Street, Edinburgh.