Rail Minister Tom Harris claims Glasgow to London journey times will come down to under four hours in the medium-term future, making the train a realistic alternative to flying.

He told The Herald yesterday that the completion of major works on the West Coast main line in December would produce a one-hour reduction to most journey times, bringing this down to current express times of four-and-a-half hours.

Combined with an earlier first train from Glasgow this would allow an arrival in London at 9.30am by the end of this year, compared to 11.30am at present, radically transforming the way people viewed business travel choices. Mr Harris said: "Since becoming a minister, I've been a weekly user of the services between Glasgow and London.

"So I not only empathise with those who've lived through the pain of repeated delays and disruption to services, I have lived through it too. But disruption was an inevitable consequence of Europe's largest wholesale renewal scheme.

"It has been one of the most challenging rail engineering projects of its kind anywhere in the world. The West Coast is the UK's main rail artery and one of the most intensively-operated routes in Europe."

Mr Harris said the change from routine journey times of five-and-a-half hours to an hour less and with a further half-hour cut in prospect "in the not too distant future" changed the whole dynamic of travel to London, tipping the balance firmly in favour of rail over air".