By JAY MERRICK

Jacques Herzog, designer of Britain's most successful art museum, the Tate Modern in London, has launched scything attacks on two of the Tate's greatest international competitors.

He said New York's Museum of Modern Art (MoMA), the world's most powerful fount of public art, was driven by a cynical and elitist strategy.

And in Bilbao, the Guggenheim Museum, designed by the architecture superstar Frank Gehry, left him cold because it was a "very bad example for museums in the future".

His remarks, made in the run-up to the Venice Architecture Biennale, stunned an otherwise demure seminar on the relationship between branding and art presentation, staged by the British Council and Brunswick Arts. The speakers included MoMA's Paola Antonelli and Daniel Libeskind, designer of Berlin's iconic Jewish Museum.

Herzog, 50, whose practice joined the international big league after the completion of Tate Modern, accused previous speakers of being "too polite" and insisted that museums such as MoMA were portraying art as decoration for buzzy lifestyles.

As for Bilbao's gleaming, titanium-clad repository, it was "just superficial. Take all that s*** out and cultivate it with ingredients from the city.

Right now, it's like an alien."

Daniel Libeskind defended Gehry's masterpiece of crumple-zone architecture. But he conceded that shopping and museum experiences were becoming interchangeable, and that branding exercises were part of them.

Libeskind's Imperial War Museum North, which was recently opened in Manchester, was, like Tate Modern and MoMA's funky new QNS gallery in New York, the subject of extremely detailed branding exercises. These exercises came with expensively packaged press releases accounting for dozens of hectares of softwood forest, and triggered streams of gasket-blowing hyperbole.

Charles Jencks, one of the world's pre-eminent architecture commentators, sides with Herzog. He said Bilbao's hugely publicised museum was "partly cynical in that it was a global branding" and contained overblown exhibitions of American "lend-lease" art - a reference to America's postwar industrial financial largess to economically shattered European countries.

The Guggenheim, he added, planned to take over the art world, "like McDonald's". Since the Bilbao Guggenheim, "the game is about competitive buildings. It's a dangerous game."

And it's getting more dangerous. In America alone, there are at present more than 50 museum expansion projects worth a reported US$5 billion ($10.5 billion). For the moment, the Guggenheim organisation is the big hitter, planning to spend almost US$700 million ($1.47 billion) on a single new art museum in New York. Designed by Frank Gehry, its wow-factor will give MoMA something to think about, though probably in terms of pulling power rather than art.