His critics may have long dismissed him as an irresponsible prankster, scarcely one step up from school dropouts carving slogans on park benches. But the British graffiti artist Banksy, who earlier this year planted a hoax rock painting in the British Museum depicting a spear-wielding caveman pushing a supermarket trolley, may finally convince the doubters that he, and his imposing stencilled images, are more than just a joke.
This week he risked the bullets of the Israeli security services to stencil nine paintings on to the Palestinian side of Israel's separation wall. They included pictures of children digging a hole, breaking through the wall, and another of a ladder apparently going up the wall and over to the other side. For an artist who built his reputation by spraying large images, among them policemen with smiley faces and masked rioters lobbing bunches of flowers, it is arguably his most political statement to date.
For Steve Lazarides, the manager of www.picturesonwalls.com, which sells Banksy's original work and screenprints and publishes his books, the Palestinian venture was a political statement totally in keeping with previous work.
"He's one of the few artists around who actually has something to say in his art. Most of his work is highly political," Mr Lazarides said yesterday. It works on lots of levels and there's humour in it, but at least 90 per cent is a commentary on society. It is way beyond a joke and has far more resonance than most of the work considered 'proper' art."
The two men met about eight years ago and Picturesonwalls has now sold more than 100,000 of Banksy's books as well as paintings to fans such as the fashion designer Paul Smith. Originals of his work sell for upwards of £10,000. "He's one of the hardest working people I've ever met," Mr Lazarides said. "He's a perfectionist, like most artists."
And while Banksy himself is apparently perfectly content with the common title "graffiti artist", his friend regards this label as inadequate. "Nobody now refers to [the late American] Basquiat as just a graffiti artist. The same goes for Banksy. It's art that is on the street, but that is as far as the similarity [to graffiti] goes."
Certainly there is a fierce political protest in the new work, even if it is leavened with typical irreverence. In rare words of explanation, the artist told The Independent: "If you like dancing you go on holiday to Ibiza, if you like walls you go to Palestine."
Speaking through his publicist, Jo Brooks, he went on: "The segregation wall is a disgrace. On the Israeli side it's all manicured lawns and SUVs, on the other side it's just dust and men looking for work. The possibility I find exciting is you could turn the world's most invasive and degrading structure into the world's longest gallery of free speech and bad art. And I like to think I can help with that bit."
He added: "Besides, I love Palestine - all of the giant walls, the dirt and the falafel stalls remind you of Glastonbury."
So, deep moral outrage burns bright, but the source of Banksy's political drive remains as much of a mystery as the other details of his life history. He insists on maintaining his privacy, not least because of the illegality of scaling walls and bridges and covering them with provocative art.
He has been named as Robert Banks, aged about 30, with a few arrest warrants to his name. The repeated assertion that he grew up in Bristol lends the idea some credibility. But a Sunday newspaper interview with him which stated his parents were a photocopier engineer and a receptionist and that he was initially apprenticed to a butcher ("I was trained to use knives, " he said, "you can create beautiful things with them" ) was dismissed by his publicist yesterday as a probable wind-up.
The guide on his website to cutting stencils perhaps offers clues to Banksy's psychology. At the very least, it offers witty advice to Banksy copycats: "Be aware that going on a major mission totally drunk out of your head will result in some truly spectacular artwork and at least one night in the cells," he warns.
"When explaining yourself to the police it's worth being as reasonable as possible. Graffiti writers are not real villains. I am always reminded of this by real villains who consider the idea of breaking in some place, not stealing anything and then leaving behind a painting of your name in 4ft high letters the most retarded thing they ever heard of."
But the police may not entirely accept the argument that "people look at a graffiti painting and admire the use of a drainpipe to gain access" .
In the absence of a CV, the work is left to speak for itself. Banksy first reached a wider public when he was commissioned to create the cover for Blur's album Think Tank, but he has reputedly turned down large sums from American multinationals such as McDonald's and Nike to produce advertising campaigns. He has also placed a painting of a can of Tesco's own-brand tomato soup in a gallery in New York, and sprayed the Tate with the question: "All artists are prepared to suffer for their art, but why are so few prepared to learn to draw?"
Karen Wright, editor of Modern Painters magazine, this year suggested that Banksy would have been a more exciting candidate for the prestigious Turner Prize than any of the artists who were shortlisted. The new work is likely to convince her that she was right.
But institutional recognition is not what Banksy is about. "You could stick all my shit in Tate Modern and have an opening with Tony Blair and Kate Moss on Rollerblades handing out vol-au-vents," he once said, "and it wouldn't be as exciting as when you go out and you paint something big where you shouldn't do."
One of nine stencilled works left this week on the
controversial 425-mile long concrete barrier that separates Israel from the Palestinian territories. Banksy called the wall "The ultimate activity holiday destination for graffiti writers."
iBanksy's Mona Lisa
Last year, after two failed attempts, he managed to plant his version of Leonardo Da Vinci's Mona Lisa, complete with 'acid' face, in the Italian Grand Masters Room in the Louvre, Paris.
Woman in gas mask
One of four works smuggled into New York's top museums in one day earlier this year. The small gold framed portrait hung in the Metropolitan Museum was discovered after a few hours.
iChrist with shopping bags
Part of the Santa's Ghetto Exhibition in London 2004, Banksy illustrates his ideas on the true meaning of Christmas.
Early man goes to market
For days, unsuspecting visitors filed past the hoax cave painting as they viewed the British Museum in London. The museum did not realise it had become a victim until it was revealed on Banksy's website.
Discount soup can
Another of the four works hung in one day in New York. It took The Museum of Modern Art four days to find and remove the Warhol-style print. A Moma spokesman said they would keep it for him to collect.
An image from the 2003 Turf War Exhibition. The location was kept secret until just a day before the event when an e-mail was sent out giving an address which turned out to be a disused warehouse in Dalston, east London.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies