An artist's provocative plans to keep a car running every day for a year to highlight air pollution have been condemned by campaigners.
Mr McGowan describes himself as a performance artist
Mark McGowan's plan to leave a tap running to highlight water wastage, ended with the threat of legal action.
Now he says he will turn on a car's engine for eight hours a day in a car park in Peckham, south-east London.
A spokeswoman for environmental group Transport 2000 said the proposals were irresponsible and hypocritical.
The "environmentally conscious" art series by Mr McGowan, a performance artist based in nearby Camberwell, has infuriated many.
Thames Water threatened him with legal action after he left a tap running at a gallery for a month, while water shortages were forcing it to consider a hosepipe ban.
Of his plan to leave a car running in a courtyard behind Peckham's library to highlight unnecessary pollution, Mr McGowan said: "I know I will be upsetting people."
But he added: "What about car owners who drive to the local video store or the corner shop or in fact the school?
"How many times do you see mums leaving cars running outside the school gates or taking one child 800 metres to school in a 4x4?"
Mr McGowan said The Running Tap wasted 800,000 litres of water
But his plans have been met with derision by pollution and transport campaigners.
Daisy Johnson, from Transport 2000, told the BBC Mr McGowan's plans were "laughable to the point of tragedy".
"Claiming to highlight people who cause unnecessary pollution by wilfully polluting the atmosphere himself...is irresponsible in the extreme," she said.
"And [it] displays a warped and hypocritical attitude towards the environment and society."
And Rob Pilling, policy officer at the National Society for Clean Air, said: "Anything that raises the profile of these issues is important, but doing something like this is a bit silly".
But for anyone worried that the stunt, due to begin on 5 November, will vastly increase Peckham's air pollution, air quality analysts say not to worry.
Ben Barratt, from King's College, said exhaust fumes become more diffuse and less harmful as they mix in the atmosphere.
"Unless anyone stood right next to the car for eight hours a day, it probably won't make that much difference," he said.