Wowereit told mass-market daily Bild that the German capital was a "tolerant and open" city that was pleased to have guests from all walks of life, even unconventional ones.

The mayor, who publicly declared his homosexuality before his election in 2001, has come under fire for the official greetings in his name included in the program of the whips-and-chains festival starting Friday.

"The international leather and fetish scene is meeting for the second time in Berlin for the Folsom Europe 2005 street festival. Welcome to Berlin!" the letter reads.

"Berlin is a tolerant and open metropolis. We are proud that people from different backgrounds and with different preferences feel comfortable here and party together... (Parties like Folsom Europe) allow the scene to present itself openly and break down skepticism and prejudice."

The head of the conservative block in the Berlin state legislature, Nicolas Zimmer, was quoted by Bild as saying that the letter was "not in line with the dignity of the office" of mayor.

Bild printed advertisements for the festival featuring bare-chested men licking each others' jackboots and a man chained to a urinal and wearing leather briefs, boots and a gas mask under the heading "Perverts".

On the opposite page, the newspaper splashed a photograph from last year's party featuring a dog-collared sex slave kneeling before his leather-clad master.

"There's no question it is a flamboyant scene, but that is also Berlin. And as long as there is nothing forbidden happening, I expect tolerance," Wowereit told Bild.