The plant would desalinate water from the Thames to replace that lost through Thames Water’s leaky pipes, and will be built on Metropolitan Open Land near Beckton, in east London.

In a statement Livingstone said he was challenging the decision to give a green light to the plant following a public inquiry "as I do not believe the evidence we put forward at the inquiry was given proper consideration.

"Thames Water should be fixing more leaks rather than finding expensive ways to spend Londoners’ money on making fresh water.

"They have the worst leakage record in the UK and the water produced by this plant won’t even come close to replacing what they waste every day.

"Londoners are becoming increasingly aware of the need to tackle climate change and reduce water consumption.

"Adding £200 million to Londoners’ water bills to spend on a technology more appropriate for the desert is simply a disgrace.  I cannot sit back and allow that to happen."