Why a decision about the Sydney Opera House has so many people furious.

The Sydney Opera House. The Everest Carnival. Two seemingly disparate things that are today tied up bureaucratic tangle that’s caused outrage on all sides. So much so that 2GB radio host Alan Jones decided to step in.

So what’s a 45-year-old national landmark got to do with a $10 million horse race?

Well, the state’s Liberal government has instructed the Sydney Opera House to promote the October 13 event via an enormous projection to be cast onto the building’s iconic white sails on Tuesday night.

It’s a move Racing NSW CEO Peter V’landys says will help “take Sydney to the world”.

“We have two of the greatest landmarks anywhere in the world — why wouldn’t we use them to promote Sydney internationally?” he told The Daily Telegraph.

The 1200 metre sprint race, to be held at Royal Randwick, is the richest turf race on the planet and will be broadcast internationally.

At this stage, it looks like the projection will feature an image of The Everest trophy, the barrier numbers and colour of the jockeys' silks. The initial proposal included the race's logo, but a compromised was reportedly reached after resistance from Sydney Opera House management.

Why are people upset?

As Sydney Opera House CEO, Louise Herron, explained to The Sydney Morning Herald: “The community regards the Opera House as its asset to be treated with respect, to be treated as the treasure it is."

Instead, she fears that with decisions like this, the tax-payer owned landmark risks losing its World Heritage status and becoming "a billboard".

In fact, Opera House policy explicitly forbids the display of "logo[s] or corporate identity": "What that means is when people come along and say ‘I want to advertise Chicken Tonight on the sails,’ we can hold firm because we never approve that," the chief executive told The Sydney Morning Herald.

So, how is The Everest projection allowed to happen?

While the Sydney Opera House Trust is responsible for governance of the building, it is a statutory body, meaning it acts on behalf of the state government.

That's why the government has the power, in this case, to instruct that the sails be used for promotional purposes.

It's done it before; in support of Wallabies at the 2015 Rugby World Cup final and to celebrate Australia's 2018 Ashes victory.

Who is in favour of The Everest proposal?

For one, both sides of government. According to The Sydney Morning Herald, NSW Labor leader Luke Foley supported the Racing NSW plan and federal MP Anthony Albanese urged critics to "chill out a bit": “The fact is that this race is beamed around the world. People do associate Sydney with the Sydney Opera House,” he told ABC Radio.

"You should lose your job!"

The CEOs of @racing_nsw and the Opera House went toe to toe with @AlanJones in an EXPLOSIVE interview https://t.co/Y38w4jp4HC pic.twitter.com/AsSN4s1ekx

— 2GB 873 (@2GB873) October 4, 2018

And they've also had vocal support from 2BG broadcaster Alan Jones. The controversial radio host let fly at Herron during a tense exchange on his program on Friday.

"We own the Opera House, do you get that message? You don't," he said.

"You manage it, and if you can't give the go ahead for this to happen, to an event that's providing $100 million to the economy, delivering a tourism boom to Sydney, to send Sydney around the world.

"If I were Gladys Berejiklian I'd pick up the phone and sack you today."

The state government has not commented on the saga.