The NSW government is standing by its decision to force Sydney Opera House management to promote a horse race despite an increasingly vocal community backlash describing the move as "crass commercialism".
Premier Gladys Berejiklian intervened late last week after shock jock Alan Jones publicly berated Opera House chief executive Louise Herron who had ruled that words or branding promoting the Everest Cup shouldn't be projected onto the sails because "it's not a billboard".
Ms Berejiklian on the weekend insisted the site's status on the international list was not at risk and said she was "incredibly comfortable" with her government's decision.
This image provided by Racing NSW shows an artist's impression of how horse race advertising will look on the Sydney Opera House. Source: AAP
Most notably, colours of the rainbow pride flag were projected onto the sails in December 2017, to commemorate the passing of laws to legalise same-sex marriage.
The structure is a centrepiece during Sydney's popular Vivid festival, where multi-coloured displays are projected onto the sails over the two-week event.
Colours of the flag of France were also projected to show solidarity following 2015 terror attacks.
National Trust NSW conservation director Graham Quint said there were clear differences between previous projections on the Opera House sails and the ones proposed.
The sails of the Sydney Opera House are lit up to celebrate the passing of the same-sex marriage laws which where passed through federal parliament Source: AAP
"Those other projections are all to do with institutions, such as NAIDOC Week, Vivid, the Wallabies, the Olympics - This is a horse race in its first year," he told SBS News.
"If you had the Taj Mahal in India, which is on the World Heritage list, the Indian government would never let it be used in this way. No other country would let this happen, so we're a bit of a laughing stock on the world stage."
Mr Quint said projecting commercial material onto the sails contravenes state laws, in that the legislation makes clear that projecting colours and images onto the sails should be "confined to exceptional, non-commercial occasions of brief duration".
National Trust NSW conservation director Graham Quint. Source: Facebook @Graham Quint
He said the universal image of the structure, which is listed as a World Heritage item, could also take a hit if the projections go ahead.
"It's a unique building, there's no other building like it in the world," he said.
"The work that's been done recently with upgrading the theatre, has been to make sure the original historical vision of the building doesn't get ruined.
"People would say that we would probably not build something like that, which is probably true. That's why it's so special. One of the requirements of the World Heritage listing, is not just the fabric itself be protected, but the presentation is correct - and this is not the way to present it."
Director of Heritage Conservation at Sydney University, Dr Cameron Logan, said part of the Opera House's significance was that it stood alone as an ambassador for Sydney.
"In the way that people imagine Sydney, it's central to the image of the city," he said.
"The controversy isn't about protecting the building and architectural integrity, people consider the horse racing ad as a misuse of the city's identity, on behalf of a commercial interest."
A petition against the plan to use the Opera House as a billboard has reached 170,000 signatures in three days.
Left-leaning think tank the Australia Institute has written to Premier Gladys Berejiklian and federal Environment Minister Melissa Price suggesting the light show could also breach commonwealth environment laws.
