The Mayor's levy on central London developments has come under fire for unfairly penalising them.
Crossrail is looking for developers to contribute £200m to the funding of the project in Section 106 agreements.
The London Assembly’s Planning and Housing Committee reaffirmed its support for the overall funding package but called on the Mayor to rethink his approach on a number of policy details.
They said they supported the principle that developers should be expected to contribute to the cost of additional infrastructure that will ameliorate the impact of their developments, but that they were concerned that, in the current economic climate, the level of the charge may affect the viability of some schemes.
They also raised concern that the charge would only on developments within the Central Activity Zone (CAZ) and the northern part of the Isle of Dogs, but, they say, some parts of the CAZ will not benefit as much from Crossrail as some of the major centres outside the Zone.
So they recommend the charge be levied on a sliding scale according to how much an area is expected to benefit from Crossrail, and on developments along the route both within and outside the CAZ.
Nicky Gavron AM, Chair of the Planning and Housing Committee, said: “The Mayor needs to look outside the Central Activity Zone for Section 106 contributions and seriously consider charging the levy on a sliding scale, or risk overburdening areas that may not even see real benefits from Crossrail, like parts of Southwark, Lambeth and Hackney.”