Following the NSW government’s controversial choice to allow the upcoming Everest horse race to be promoted on the sails of the Sydney Opera House, an online petition supporting its CEO Louise Herron – who rejected the ads – has gained nearly 150,000 signatures in a couple of days (at time of publication).

Around 2500 people are also expected to attend a “light-based protest” at Bennelong Point tomorrow evening.

The petition launched last Friday after a fiery interview between Herron and 2GB radio broadcaster Alan Jones that morning. In two days it garnered 55,000 signatures, and by this morning that figure had more than doubled, with thousands throwing their support behind Herron who argued the projections would put the building’s heritage status in jeopardy.

“Let's remind Alan that the Opera House truly does belong to everyone, by supporting Louise Herron's staunch defence of one of our city and country's few instantly recognisable heritage landmarks,” wrote petition organiser Mike Woodcock in its description.

In the live radio interview, Jones interrogated Herron about her decision to not allow the logo and words “The Everest” – which is the world’s richest horse race on turf, and the pinnacle event of Sydney’s spring-racing program – to appear on the famous sails.

The shock-jock broadcaster accused Herron of making a bad decision, saying, "If I were [NSW Premier] Gladys Berejiklian, I would pick up the phone and sack you today. We own the Opera House. Do you get that message? You don't. You manage it.”

Herron pointed out, she’d already agreed to the projection of the jockeys’ colours, which Racing NSW CEO Peter V'landys argued would be “meaningless”. V’landys said he wanted a barrier draw, complete with the competing horses’ names and numbers, and an image of The Everest trophy to appear instead.

Following the radio interview, the Opera House management’s decision was overturned by Berejiklian directly.

The ads will be visible for the first time tomorrow night but will not feature The Everest logo. “All that is left is the trophy, the colour of the jockey silks and the barrier the horse has drawn,” Mr V’landys told the Sydney Morning Herald.

The planned protest has been described by its organiser – known only on social media as “Desk” – as a passive attempt to disrupt the questionable use of the sails.

Attendees are encouraged to use light sources such as smartphones, torches and even boat lamps to collectively “express displeasure” at The Everest controversy, but Desk has made clear it won’t be an “official protest” as “there is no organiser and there is no permit.”

Prime Minister Scott Morrison (a former head of Tourism Australia) and NSW opposition leader Luke Foley have thrown their support behind the promotion. “This is one of the biggest events of the year. Why not put it on the biggest billboard Sydney has?” Morrison told ABC.

Simon Holmes a Court – who was behind Australia's first community-owned wind farm (and who describes himself as an energy-transition specialist) – was one of many who objected to the horse-race ads. Yesterday he tweeted: “I’d like to take out an ad on the opera house sails – a video projection of kids detained on #nauru, one of our national pastimes. i’m willing to pay the same as @NSW_Racing. serious offer – who do i speak with?”