Marathon runners may take a detour on the home straight

Tamil demonstrations at Parliament Square could require change of route

The organisers of tomorrow's London Marathon have made plans for a last-minute change of route in the final stages of the race in case any disruption is caused by Sri Lankan Tamils protesting outside the Houses of Parliament.

The 36,000 runners could be diverted away from Parliament Square, which has featured in the race for each of its 28 years, after a series of at times unruly demonstrations by Tamils over the past fortnight. They are angered by the current offensive by the military against Tamil Tiger separatists trapped with 50,000 civilians in a tiny coastal battle zone in northern Sri Lanka.

Scotland Yard said yesterday there was no intelligence suggesting any plan by demonstrators to directly interfere with the marathon, but it is understood that senior officers are concerned about the possibility that large numbers of protesters could converge on the Palace of Westminster, swelling the crowds watching the climax of the race as it enters its closing mile towards the finish line in The Mall.

Members of the Tamil community involved with the protests, which have seen up to 800 demonstrators blocking roads and staging sit-ins, told The Independent yesterday that their campaign outside Parliament would continue this weekend after the Sri Lankan army high command vowed there would be "no pause" in the onslaught against the rebels.

One organiser said: "After the events of the past week, the turnout is going to be very large this weekend. We have no way of knowing how many will come or of controlling them once they come. We have not been contacted about the marathon but we will remain outside Parliament."

Boris Johnson, the Mayor of London, insisted that the "same route" passing many of tourist attractions would be used for the race, which finished on Westminster Bridge opposite Big Ben between 1983 and 1993.

Runners ranging from professional athletes to amateurs in fancy dress are due to enter the closing stages of the 26 miles and 385 yards course from Greenwich by turning right out of Victoria Embankment and crossing Parliament Square before running alongside St James's Park.

Marathon organisers said they were not "actively considering re-routing" the race but confirmed meetings had taken place with the Metropolitan Police and the Mayor because of concerns about disruption. A spokesman said: "As major event organisers we have to consider potential causes for diversions that may be required on the day of the race and plan for such eventualities."

It is understood plans have been made for an alternative route via Admiralty Arch and Horse Guards Road. A police source said: "We are leaving it in the hands of the organisers but if there is a need for a change of route at short notice we have contingencies in place."

Last year, a gas leak forced organisers to change the route of the race just 20 minutes before the start.