Prime Minister Scott Morrison said he agrees with the decision to project promotions for a $13 million horse race on the Sydney Opera House's sails this week.

The NSW Government's decision to beam the Everest trophy's barrier draw on the iconic Sydney landmark has received huge public backlash, with an online petition against the move accumulating over 40,000 signatures.

Mr Morrison defended Premier Gladys Berejiklian's acceptance of Racing NSW's submission, calling it a "no-brainer".

"This is one of the biggest events of the year," he said, speaking at a press conference in Blayney, in Central West NSW.

"Why not put it on the biggest billboard Sydney has?

Alan Jones (left) called for the sacking of Opera House chief executive Louise Herron (right) if she did not agree to promote a horse race on the sails of the iconic building. ( AAP: Tracey Nearmy/Tracey Trompf )

"These events generate massive economic opportunities for the state, for the city. Look at the biggest event this place sees every year down at Bathurst.

"I'd put the Bathurst 1000 on the Harbour Bridge if I thought it was going to get more people there.

"It's just common sense, I don't know why people are getting so precious about it."

The Prime Minister's comments follow Ms Berejiklian's earlier on Sunday, who stated it was "in the best interests of the community" to beam the Everest Cup on the heritage building.

"What is right for government is to do what is in the best interests of the community and that's what we've done on this occasion," Ms Berejiklian said.

"I'm absolutely confident it's the right thing to do.

"I am extremely passionate about the iconic stature of the Opera House. I believe what we're doing is in the right interests of Sydney and NSW and also there is precedent.

"Have a look at the display before you judge it."

Detractors have accused the Premier of giving into 2GB radio personality Alan Jones, who called for the sacking of the Opera House's director Louise Herron for initially rejecting the Racing NSW request.

On Friday, Jones asked Ms Herron in a shocking radio interview: "Who do you think you are?"

"If I were Gladys Berejiklian, I would pick up the phone and sack you today," he said.

Ms Herron said the Opera House would put the jockey's colours on the sails, but said "what we won't do is put text or video of horses running or horses numbers or names or the Everest logo on the Opera House".

"It's not a billboard."

Soon after, the Premier asked Ms Herron to go forward with beaming the horse race promotions on the Opera House sails.

Berejiklian says negotiations were happening 'for a long time'

Ms Berejiklian, in addressing the way Jones spoke to Ms Herron, said everybody had a right to express their views and she believed it should be done "respectfully".

She said the government had been "in negotiations for a long time over this matter".

"The version that is going to be played or displayed on Tuesday is… toned down with what the Government was presented with."

"Can I say, no one is more passionate about the Opera House than I am. My dad was actually a welder on the Opera House," Ms Berejiklian said.

"My family history goes back to the first days when the opera house was being built."

"This wouldn't be Sydney without having different views on an issue like this but I'm absolutely confident it's the right thing to do.

"It's the right thing for Sydney and I hope in the future everybody has these debates in a respectful manner."