The Crossrail levy, under which developers in Central London and the Isle of Dogs would pay £200m towards the cost of the project, have been branded as "too narrow" by the capital's leading regeneration and planning bodies.
Baroness Jo Valentine, the cheif executive of London First, the capital's inward investment agency, said plans announced last month by London mayor Boris Johnson were causing "great concern".
She told delegates on the London Stand at MIPIM in Cannes: 'Recession is a hesitation in London's growth. We still need the infrastrucure that Crossrail brings. We support the principle of a charge [for developers] but this must be reasonable, equitable and viable for the development community.'
Baroness Valentine added that the plans as they stood had the potential to lead to prohibitively high charges.
Archibald Galloway, deputy chairman of the planning and transport sub-committee of the City of London Corporation, said the proposals were an unfair burden on developers during a period of economic crisis.
'The cost of the project needs to be spread farther out than the the Central Activity Zone and the Isle of Dogs,' he said, referring to the areas where a levy of 20/sq ft would be applied to new developments of more than 5382 sq ft.
'Offices developers alone are being asked to carry the weight of the property industry's contribution to Crossrail, even though many more others would benefit from it.'
An alternative, said Galloway, would be a levy which applied to developments within 800 metres of each of the new Crossrail stations. 'Crossrail will bring benefits across London and the south-east, so the cost of paying for it should be spread around,' he said.