Ministers are considering a proposal which would see hundreds of thousands of householders and businesses paying a windfall tax if their properties increase in value because of new transport links.

The tax, which has been successfully used in America, could be used to finance the CrossRail scheme involving a tunnel linking Paddington in west London to Stratford in the East End, the upgrade to existing Thameslink services between Brighton and Bedford via London Bridge, and the East London line Tube extension.