A NOTORIOUS teenage street artist was thrown out of the House of Commons – after lighting up a spliff in the public gallery.

Stencil artist Cartrain, a member of Finsbury Park urban art collective Gallery 90, sparked the joint in front of Deputy Prime Minister Nick Clegg at Prime Minister’s Questions on Wednesday (November 10) – and shouted “decriminalise cannabis”.

The 18-year-old said: “I don’t know how I got in!

“They X-rayed me and seemed to spot something. They looked a bit surprised – but then they just let me through.”

The artist, whose identity is a secret, had waited three hours to get into Parliament.

After lighting up in the Strangers Gallery, he carried on puffing away as security advanced.

The teenager, who is studying for an art foundation degree at the Working Men’s College, in Camden Town, is no stranger to controversy - having been threatened with prosecution after stealing a pencil box from a sculpture by Damien Hirst last year.

And he was fully prepared for his latest escapade to land him on the wrong side of the law.

“I told them I was happy to be arrested,” he said. “But they said they didn’t want to give me the satisfaction.”

Cartrain claims he was standing up for the “human right” to smoke cannabis, and likened the decriminalisation campaign to the American civil rights struggle – comparing his own actions to Rosa Parks’ refusal to hand over her bus seat to a white person.

The young artist’s works have appeared on walls across Islington.

His murals have been seen in streets such as Drayton Park, in Holloway, Mountgrove Road, in Finsbury Park, where Gallery 90 is based, and a host of sites around Finsbury and the Angel.

He said: “I go out after darkness falls and spend two or three hours on one piece whenever I go painting.”

Referring to his controversial way of making a point, he added: “Someone’s got to do it.”