More than 100,000 people have signed a petition opposing a plan advertise The Everest race, the richest on turf in the world, on the sails of the World Heritage-listed building.
NSW Premier Gladys Berejiklian on Friday pulled rank on Opera House management to allow Racing NSW to use the venue to promote the race after a vigorous campaign by Sydney radio broadcaster Alan Jones.
Ms Berejiklian denied she had caved in to Jones, the 2GB host who has been named one of the country's most influential broadcasters.
Jones on Friday attacked Opera House chief executive Louise Herron, who had ruled out allowing words or branding to be projected onto the venue because "it's not a billboard", and called for her to be sacked.
Prime Minister Scott Morrison weighed into the stoush saying he had no problem with the building being used to promote the race because such events generated economic benefits.
"This is one of the biggest events of the year why not put it on the biggest billboard Sydney has," he said on Sunday.
Racing NSW is surprised at the backlash. Chief xecutive Peter V'landys said he had been negotiating with the state government for more than a year and initially wanted to use the Sydney Harbour Bridge to promote the Everest race.
"The Opera House was the alternate venue put forward by the NSW government, which wanted to support the promotion of the event internationally, as it had done for other sporting events," he wrote in an opinion piece published in The Sydney Morning Herald on Monday.
"We are promoting a unique Sydney event, The Everest, not gambling."
Mr V'landys also said a "vast majority" of the negotiations happened before Jones got involved last week.
"Call me naive, but I certainly didn't expect there would be such a reaction to us using the Opera House sales for 10 minutes to promote The Everest event internationally."
As of Monday morning, more than 100,000 people had signed a change.org petition to "protect" the iconic building from "Alan Jones and his Gambling mates at Racing NSW".
"I wanted to show support for Louise Herron's resistance to putting gambling advertising on our city and state's most recognisable landmark," petition organiser Mike Woodcock wrote.
The son of Peter Hall, the architect who oversaw the completion of the Opera House, described the plan as a "desecration".
"My father would have been sickened by it ... he would not have condoned advertising on the building in any way, lucky he's not around to see the desecration of our beautiful iconic masterpiece," Willy Hall told Fairfax Media.
