Dear Brian Mawhinney

The Fort William to London sleeper service has won a reprieve. A defender of the line warns the Transport Secretary that he is in for a long fight over its future

No doubt your long-faced officials have briefed you on yesterday's ruling in the Court of Session in Edinburgh. If, on appeal, the judges confirm that Scotrail's chicanery over the West Highland sleeper service was unlawful, it will delay their proposed closure of the service for several months.

At any subsequent inquiry, the London Friends of the West Highland Line, of which I am chairman, will grasp the opportunity to air the real costs of running the service - which are very different from those being used by the Government and the Office of Passenger Rail Franchising.

The refusal of you and your ministerial colleagues to meet us has denied us the opportunity to explain why we and several other groups are fighting this closure so strongly. Quite apart from losing the unique experience of the West Highlander, the effect of withdrawing the sleeper service on Fort William and the surrounding area - where one-third of jobs are in volved in the tourist industry - would be devastating.

But the battle has implications well beyond the West Highlands. If the sleeper is closed because, in the Rail Franchise director's words, it is "disproportionately uneconomic", many other services and lines in rural areas, on the same criteria, would also be closed.

The figure you have been using of £453 subsidy per passenger is fantastic. To arrive at that sum, huge costs have to be allocated to the sleeper service that rightfully belong elsewhere - such as inflated Railtrack charges.

We know from leaked correspondence between the Rail Franchising Director and your colleague Ian Lang that, even on your figures, the savings from cutting the service would be a fraction of £453.

But we also know from our own detailed analysis that the cost to the public purse for the sleeper service last year was a little over 10 per cent of your figure - roughly £46 per head, allowing for a modest adjustment in passenger numbers to account for the signal workers' strike. Almost identical figures have been produced by others - including the Expert Adviser to the House of Commons Select Committee on Transport and former senior BR managers.

In fact, the current passenger subsidy on the service is more modest still, partly because the sleeper always earns most of its revenue during the summer; and partly because passenger numbers are up more than 50 per cent on the same period (that is before the signal workers' dispute) last year.

BR will, no doubt, tell you that this increased usage is merely a flash in the pan. But experience from the battle to save the Settle to Carlisle line has shown that increases in passenger numbers during the campaign continued after the line was saved - such that, but for the strike, last year's usage rates would have been six times higher than before the mooted closure.

We think that in private you might even welcome yesterday's judgment. It offers you an opportunity to go some way to restore the Government's fortunes north of the border - and you could intervene to save the sleeper in the guise of upholding the law.