Protesters lose turf war in Sydney Opera House 'billboard' row

The Aus$13 million (US$10 million) Everest race, which boasts the world's biggest turf race prize, takes place in Sydney on Saturday and organisers persisted through tense debate to promote it on the white sails of the Opera House.

"Sydney is not Las Vegas, and our cultural icons should not be used to promote the racing industry, an industry which makes profit from problem gambling," prominent state MP Alex Greenwich told reporters ahead of the light show.

The sails have been used previously to promote other major sporting events, including the Olympics, but Opera House management opposed much of the Everest promotion, claiming using the building as an advertising "billboard" threatened its heritage status.

The New South Wales government intervened, arguing the event provided the state with a huge tourism boon, forcing management to allow the race's trophy, colours and numbers to be beamed onto the structure. 

The move sparked a heated public debate, with politicians of all stripes weighing in.

"This is one of the biggest events of the year. Why not put it on the biggest billboard Sydney has," said prime minister Scott Morrison, describing the promotion as a "no brainer".

Opposition Labour leader Bill Shorten said the Opera House showed the world Australia was capable of creating "great beauty".

"I don't look at the Opera House and see a billboard, I see a remarkable Australian achievement."

A petition against the Everest light show attracted close to 300,000 signatures prior to Tuesday evening, while hundreds of protestors chanting "not for sale", armed with flashlights and mobile phones, attempted to disrupt it with light projections of their own.

"I think it is a disgrace," 42-year-old protestor Tessa Boyd-Cane told AFP. "The Opera House is a national icon, it's a national treasure. It is not something that should be reflected in what is basically a promotion for gambling."

Race organisers had planned do a barrier draw alongside the evening light show, but held it in secret earlier in the day to "circumvent any security risks that may exist."

They also temporarily suspended betting on the race until the barriers were publicly revealed during the Opera House display.