Channel rail ruling could close Thameslink for a year

London's Thameslink will be disrupted for up to a year if work on the Channel Tunnel Rail Link is not allowed to continue round the clock.

London & Continental Railways, which is in charge of the £3.3bn second phase of the project, said that unless the Government allows it to work 24-hours a day, it "cannot prac- ticably complete the work".

The company is running nearly three months behind schedule to build the high-speed line between London St Pancras and north Kent. To get the project on track and to complete essential engineering works, LCR has applied to allow work through the night.

Camden Council rejected the application last year, fearing that it would disturb its residents. But LCR appealed and its application was heard by a government-appointed inspector last week.

Alan Dyke, the managing director of Union Railways, a subsidiary of LCR, said: "Some 24-hour working was always planned and we cannot practicably complete the works without it." This, he said, was because the work involved "possessions" - working while neighbouring railways are closed. "We are already closing Thameslink for 25 weeks, and without some 24-hour working then the period of closure would have to be extended."

Mr Dyke refused to say for how much longer Thameslink would be closed if the application were rejected, but one source close to the project said it would be "many months". This would increase the cost of building the link.

Thameslink is one of the busiest rail routes in the capital, running north-south through London. The line, carrying 120,000 passengers a day, will be severed in September to allow LCR to complete its work. This will mean no through-trains until March 2005.

If LCR's application is rejected, "construction time-scales would be extended and railway closures would be more frequent or prolonged," Mr Dyke said. "This would be in nobody's interest, not the residents', not passengers' and not ours." Extending the works would exacerbate rail delays in north London, with problems on the Northern line on the Underground system.

LCR would also be forced to pay the Thameslink train operator, Govia, compensation. The planned 25-week Thameslink closure was built into Govia's franchise agreement. But further delays could trigger penalties.

The second phase of the Channel Tunnel Rail Link is scheduled to be in operation in 2007. The government inspector will rule on the application next week.