Delaying the construction of Crossrail would cost London's economy more than £1.5bn a year - or about £4m a day - according to an independent report.

Work on the cross-London rail link, designed to link Heathrow, the West End, the City and Canary Wharf, is planned to begin next year. However, the scheme was estimated to cost £10.2bn at 2002 prices and a financing package is still to be agreed by the Treasury.