When he originally unveiled the scheme, the Mayor promised that no public funds would be spent in its construction.
In a statement issued in July 2010, Johnson said: “The aim is to fund the construction of the scheme entirely from private finance and discussions are ongoing with a number of private sector organisations that have expressed interest in the project.”
The Mayor also told Assembly Members that Transport for London “does not have the budget to implement this scheme itself.”
Despite this he later confirmed that Londoners, via TfL, would provide the scheme’s “upfront funding” which would then be recouped “from a range of sources including the appointed commercial partner, fare revenue and sponsorship.”
Costs have soared from the originally estimated £25m to at least £60m.
On Friday Johnson announced Emirates Airline as the cable car’s sponsor in a ten-year, £36m deal which will see it named the Emirates Air Line.
Emirates will also receive a range of naming and branding rights, including the right to name its stations and the creation of a joint logo.
Despite failing to attract sufficient sponsorship to meet the original pledge, Johnson sought to portray the deal as good for Londoners, describing it as “tremendous news”.
Speaking after the Mayor’s announcement, John Biggs AM, Deputy leader of the London Assembly Labour Group, said: “The costs have just gone up and up on this project.
“I’m sure when it’s finished it will be a nice addition to east London but it’s not a solution to the absence of proper river crossings in the area and commuters really want every penny spent keeping fares down and improving services, especially when finances are so tight.”
Green party Assembly Member Darren Johnson said: “The Mayor keeps promising that new projects like cycle hire and this cable car can be wholly funded by the private sector, but the reality is that innovation needs public sector support.
“I am disappointed that the Mayor can’t guarentee that it will be built in time for the Olympics. It was May 2008 when I first drew the mayor’s attention to the report recommending the idea of a cable car and it has taken over three years to really get things moving.”
Mike Tuffrey, Liberal Democrat London Assembly budget spokesman, said: “Transport for London admit that this sponsorship deal only meets 80% of the construction cost. This leaves many millions of pounds worth of funding to be found from TfL’s budget.
“At a time when fares are set to rise by well over the rate of inflation people will be asking why the Mayor has failed to live up to what he had promised and ensured the cable car was entirely self financing.”
TfL says it is hoping to attract further sponsorship and is seeking further funding from the European Regional Development Fund.