The New Warhol or the Emperor’s New Clothes: Damien Hirst’s place in the artistic pantheon will always divide the critics. What no one disputes is his brilliance as a salesman.

Sotheby’s announced details yesterday of a ground-breaking auction of new Hirsts that is expected to realise between £65 million and £90 million over two days in September.

All the work in Beautiful Inside My Head Forever has been made in the past two years. Most of it looks like the equivalent of a lucrative greatest hits tour: animals in formaldehyde, spot paintings, spin paintings, butterfly wing collages, skulls and plenty of bling. The 233-lot sale also comes with a convenient dollop of controversy.

By cutting out the dealers, who might take between 40 and 60 per cent of an artist’s sales, and going directly to the buyers, Hirst is challenging one of the art world’s most important relationships. Whatever the contractual obligations, Hirst has decided to go it alone, apparently with their blessing. Jay Jopling and Larry Gagosian, Hirst’s gallery owners in London and New York, are officially supportive but find themselves in a predicament. If the auction goes well it loosens their bond with one of their most high-profile artists. If it goes badly it damages his value to them in the future. Mr Gagosian has already indicated that he will be a bidder.

Hirst believes selling at auction feels “like a natural evolution for contemporary art”. Other dealers have accused him of treating longstanding business partners shabbily and staging “an end-of-boom fire sale”.

David Mugrabi, a dealer-collector, told The Art Newspaper that Hirst was enjoying an elaborate conceptual joke. “He’s seeing if he can get away with murder, just as Duchamp did with his urinal,” he said.

There are pertinent questions about the timing of the venture, coming soon after several new and vintage Hirsts went unsold at Art Basel, the world’s biggest art fair.

Richard Shone, editor of The Burlington Magazine, the fine arts periodical, said that the auction was the latest in a long line of publicity stunts that were threatening to swamp Hirst’s critical standing as an artist: “His reputation is a little wobbly now.”

Last year the artist generated headlines around the world by selling a skull encrusted with diamonds for £50 million. It was reported later that the artist was part of the investment group that bought it.

Mr Shone said that Hirst’s profile would overshadow the intriguing possibilities raised by the auction. “I think it does offer a way forward for other artists but I wish it had been someone like Rachel Whiteread, another great figure from that generation but one who positively avoids publicity, who was behind it. Then people would really have sat up and taken notice.”

The auction takes place in London on September 15 and 16. Estimated prices range from £15,000 for a range of preparatory drawings to the £12 million upper estimate placed on The Golden Calf, a calf pickled in formaldehyde with a golden disc resting on its head and its horns and hooves cast in 18-carat solid gold.

“This is very much Damien Hirst as we know him but done at a level we haven’t seen before,” said Cheyenne Westphal, chairman of contemporary art for Sotheby’s Europe. “ The Golden Calf is a phenomenal work of art. We consider it to be one of the most important things he’s ever done.”

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