Millions of people across the world switched their lights off as part of a global environmental campaign on Saturday.

But Tom Brake, MP for Carshalton and Wallington, was not among them - despite calling for his own constituents to take part.

The Liberal Democrat issued a press release promoting the Earth Hour initiative on March 8. 

But his own home remained conspicuously alight during the 60-minute switch-off, as seen in a picture taken by a Conservative councillor.

In the release, headlined "Tom Brake MP Backs Calls to Protect the Planet", he said: "It is crucial that we work towards a sustainable future and make the environment a priority.

"I encourage residents of Carshalton and Wallington to turn off their lights or show their support for the future of this planet in any other way on the 19th at 8.30pm."

The release said Mr Brake would be "joining millions around the world" in backing the campaign and was issued with a photo of the MP holding a placard, on which is written: "This Earth Hour I'm supporting a low-carbon future".

But when the Sutton Guardian questioned Mr Brake about his own lights, the Lib Dem said: “I never said I was going to take part in Earth Hour. 

"In fact, turning the lights off as opposed to switching energy supplier has much less of an impact.

“What the press release basically said was people could either take part in Earth Hour or do other things.

“It would only have a small impact. Whereas if everyone swapped from getting their energy from a coal-powered power station to a renewable energy supplier...”

Mr Brake added he "wasn't able to turn the lights off at this time," but declined to elaborate.

He would not confirm whether he had been watching rugby during the switch-off, which coincided with England clinching the Six Nations grand slam. 

Conservative councillor Neil Garratt, who took the photograph of Mr Brake's house, said: “I was walking home and thought I would check if, on the off-chance, he wasn’t taking part in the initiative he has campaigned hard for.

“To be brutally honest, absolutely no one was taking part in the area, give or take a few houses which had their lights off.”