SCOTTISH rail passengers will see only limited improvements as part of a major revamp of west-coast main line services from today, and promised hourly trains may be postponed until next year.

The milestone changes were hailed by Tony Blair, the Prime Minister, as a “great day” for Britain’s railways, but passengers north of the Border will have to wait longer to enjoy their full share of the benefits.

The first fruits of the £7.6 billion line upgrade are already two years late, and weekend passengers face months more disruption as work continues over the northern half of the route.

New Pendolino tilting trains will take over all weekday services between Glasgow and London from today. The service will be increased by two per day to nine.

The last trains will leave nearly an hour later than the previous departure time, and a new daily service in each direction will run between Edinburgh and London via the west-coast line.

The fastest Glasgow-London journey times will be cut by half-an-hour to four hours, 41 minutes - but this will apply to only two trains a day.

Some of the other services will take as long as the previous typical journey length of five hours and 30 minutes.

In addition, Virgin Trains’ plans to run an hourly service between cities have been delayed until at least December - or even a year later - when further journey time improvements are also planned.

Chris Green, Virgin’s chief executive, stressed last year that replacing the exist- ing “ragged timetable” was crucial to attracting more passengers.

The delay is because only the southern half of the 400-mile line has been upgraded to enable the new trains to tilt to corner faster - and accelerate from 110mph to 125mph.

Work north of Crewe will continue until the end of next year, with buses replacing trains on most weekend services until at least mid-2005. The project will take until 2008 to complete.

Passenger groups have been angered that a diversionary route, via Dumfries, is not available because it has not been upgraded to take Pendolinos. A Virgin spokesman said today’s changes were the biggest single improvements for 30 years, and that hourly services “remain our aspiration”. He said: “This timetable is an interim one with more improvements to follow.”

The Strategic Rail Authority, which is co-ordinating the route upgrade, said: “Any expectation of hourly services in the September 2004 timetable change was unrealistic. They are not feasible until necessary infrastructure improvements are made.”