Plans to build a £450m bridge in east London have been given the government's financial backing.
There are several possible designs for the bridge
The Thames Gateway Bridge would link Beckton, in Newham, to Thamesmead in Greenwich.
The cost could be partly covered by tolls as well as funding from Transport for London (TfL), which predicts the bridge will create 25,000 new jobs.
The government says it has made a conditional offer to provide £200m in Private Finance Initiative credits.
The bridge is part of mayor Ken Livingstone's plans to redevelop the Thames Gateway, a 40-mile-wide area from east and south-east London to Kent and Essex.
The bridge would be 650-metres long and have two lanes each way for cars and commercial vehicles, a cycle lane, a footpath and a lane for public transport.
The bridge will link Beckton and Thamesmead
The crossing would be built and operated by a private company, working with TfL in a Private Finance Initiative (PFI) deal.
It has been criticised by some environmentalists and Friends of the Earth say it will be used by businesses to transport more road freight.
But TfL says it could cut up to 30 minutes off local journey times and the mayor believes it to be a "vital" link to an area which needs better housing and jobs.
He said he was delighted to hear the government was backing the project, adding: "East Londoners have consistently given overwhelming support for the bridge."
The bridge has to be between 50m and 70m high, so it does not get in the way of planes flying in to London City Airport, or ships passing beneath.
It could be built by 2014.