Police: 1 Custard: 0

The climate change protestor who threw green custard over Peter Mandelson on Friday has been arrested, it has emerged.

Leila Deen, 29, emptied a cup of the liquid over the business secretary’s head as he arrived for carbon industrial summit in central London.

The Metropolitan police, which launched an investigation into the incident on Friday, released a statement on Sunday saying: “[We] can confirm a 29-year-old woman attended a central London police station by appointment yesterday afternoon, March 7th, in connection with an investigation into an incident in Carlton House Terrace, SW1, on Friday March 6th.

“She was arrested by officers from Westminster CID and was later bailed to return to a central London police station in early April pending further enquiries.”

Earlier, Lord Mandelson admitted he was “slightly surprised” Ms Deen was not spoken to by police following the incident on Friday morning.

Speaking on BBC1’s Andrew Marr Show on Sunday, Lord Mandelson expressed “mild irritation” at the incident, which necessitated a change of tie.

“What was a bit surprising was that media outlets took her into their studios and started interviewing her,” he said.

“In Britain we do not live in a police state and thank goodness for that.

“[When I was Northern Ireland secretary] I had 24-hour permanent security and on balance I would prefer not to go back to those days.”

Former deputy prime minister John Prescott, the victim of similar incidents in the past, said it was “unacceptable” the Plane Stupid protestor was allowed to walk away from the scene.

Speaking to the BBC on Friday, Ms Deen had said: “When democracy is failing you have to resort to any means necessary as long as it is peaceful and does not harm other human beings.

“Peter Mandelson is the same person who effectively bullied Ed Miliband and other members of the Cabinet to accept a third runway that nobody wants, a third runway that no one was consulted on and no one is able to say no to.

“It’s not right that someone like Peter Mandelson can stand up and talk about being green.”