The cost outlay for the controversial Silvertown Tunnel appears to have risen by £200m to £1.2bn.

Transport for London (TfL) last night publicly released the contract it had finalised with the Riverlinx Consortium in November.

Read more: Controversial Silvertown Tunnel project gets the go-ahead from TfL

The twin bore road tunnel, which is opposed by many environmental groups and local councils, will connect Greenwich with the Docklands precinct.

The contract lists the “total value of the procurement” as £1.2bn – a full £200m more than expected.

A Transport for London (TfL) spokesperson said the additional £200m was not related to the cost of construction itself.

They said: “There have been no increases in the overall price of the project, and the basic construction value is around £1bn as we have always said.

Read more: Silvertown Tunnel: Bringing London together or tearing it apart?

“The figure referenced in the contract includes expenditure already outlaid by TfL, plus the cost of debt up to the forecast opening date in 2025.”

The news that the cost of the contract had hit £1.2bn sparked outrage from some quarters.

There has been a fierce campaign against the tunnel by the Stop the Silvertown Tunnel coalition, Greenwich Council, Newham Council and local MPs.

Campaigners have complained about the tunnel affecting air quality and congestion in the areas around the tunnel, however TfL modelling suggests this will not be a problem.

Stop the Silvertown Tunnel coalition chief Victoria Rance called the £1.2bn contract cost “shocking news”, while Liberal Democrat mayoral candidate Siobhan Benita said the project was becoming a “financial black hole”.

“As mayor, I would cancel it and prioritise investment in greener public transport and initiatives to encourage cycling and walking,” she said.

Despite the protestations from some quarters, the tunnel also has a lot of support from business groups who say it will benefit the capital’s economy and alleviate congestion.

Read more: Silvertown Tunnel campaigners threaten Sadiq Khan with a judicial review

Natalie Chapman, South England and urban policy chief at the Freight Tranport Association, believes the tunnel will provide a dramatic boost to a number of sectors.

“This [tunnel] is so vital in terms of products and supply chains,” she said.

“East London desperately needs connectivity…If we can spread out the river crossings it will also be a good thing for the environment.”