10/10/2018 11:12 AM AEDT | Updated 10/10/2018 11:12 AM AEDT

Torchlight Protest At Racing Ad On Sydney Opera House

A firestorm of criticism erupted after the NSW government overruled the building's management to allow advertisements for the Everest Cup.

SYDNEY (Reuters) - Hundreds of Australians flickered torches on Tuesday at the sails of Sydney's Opera House, aiming the light rays to disrupt horse-racing advertisements projected on its facade, in a protest against the use of the building to promote gambling.

A firestorm of criticism erupted after the government of the state of New South Wales overruled the management of the World Heritage listed building to allow the advertisements for the A$13-million Everest Cup.

Despite the protesters' efforts, televised pictures showed the projection, which began about 20 minutes earlier than planned, remained clearly visible and displayed horses' racing colours and barrier numbers.

James D. Morgan via Getty Images

"We are known for the Sydney Opera House; to use it to advertise a horse race is just taking advantage of it," said Aideen Keane, 16, brandishing a torch as she sat on the Opera House steps, with her mother, Lesa Hogan.

"I'm not against horse racing, but I don't want the advertising here," added Hogan.

The government's decision came after a top radio "shock jock", Alan Jones, urged the Opera House's boss to resign or be sacked for objecting to the promotion. Many politician see Jones as having great influence over voters.

Mark Metcalfe via Getty Images
A large crowd gather to protest against racing advertising on the Opera House sails.

He later apologised, but the backlash had already hit, splashed across newspaper front pages and news bulletins for days, with about 290,000 people signing an online petition against the promotion.

The outrage had already prompted racing authorities to drop plans to hold the barrier draw publicly, so as to avoid "security risks", and betting was suspended from noon until the announcement of the draw result in the evening.

Nevertheless, despite the torchlight, the results of the barrier draw were clearly visible, with short-priced runner and previous champion Redzel securing the prized inside barrier, closest to the rail, and bookmakers having resumed taking bets.

James D. Morgan via Getty Images
Protestors use torches and other lights to shine onto the sails of the Opera House during a promotional light show.

The Opera House did not immediately respond to a request for comment, but has previously directed Reuters to the state government.

The backlash was "a little bit hysterical," New South Wales sports minister, Stuart Ayres, who is responsible for racing regulation, told reporters in Sydney.

"This is a good opportunity for New South Wales and Sydney to come together," he added.

The Opera House sails have been used in art installations and to advertise events such as the Rugby Union World Cup, but not for commercial advertising.

Reporting by Jonathan Barrett; Additional reporting and writing by Tom Westbrook; Editing by Clarence Fernandez