The Liberal Democrats are calling for a River Thames tsar to be appointed by the Government to hold the country’s biggest water firm to account.

Ed Davey announced the policy during a recent visit to Woking, where he met the Lib Dem’s parliamentary candidate, Will Forster, at the River Wey. The Woking constituency saw a 109% increase in sewage spills last year.

The policy is part of the party’s plan for water industry reform, including transforming water companies into “Public Benefit Companies” by ensuring environmental experts sit on water utility boards.

The Lib Dems have also called for Ofwat to be abolished in favour of a tougher water regulator.

The proposed Thames tsar would have various roles, including attending Thames Water board meetings, hosting public meetings with river users and environmental groups, and ensuring the Environment Agency follows up reports of sewage pollution into the Thames and its tributaries.

The policy announcement follows the Government’s decision to appoint a River Wye tsar amid concerns of agricultural pollution. The Lib Dems are calling for the Thames tsar to have a high profile, with Feargal Sharkey and Steve Backshall suggested as candidates.

Last year, the Lib Dems revealed that Thames Water discharged 72bn litres of sewage into the Thames.

Lib Dem leader Mr Davey said: “The River Thames has become the scene of environmental vandalism, with yet another water company not being held properly to account.

“With a Thames tsar, the public will have new hope that someone will be acting for them and for their environment.”