Chief executive Peter V'landys said he had been negotiating with "at least four government departments" for more than a year to use the bridge to promote the race next Saturday.

"Only at the last minute did we learn that approval had not been given," he said. "The Opera House was the alternate venue put forward by the NSW government, which wanted to support the promotion of the event internationally, as it had done for other sporting events."

Premier Gladys Berejiklian’s controversial decision on Friday to allow a promotion for The Everest to be beamed onto the world heritage-listed building – overturning the decision by Opera House chief executive Louise Herron after a hostile interview by broadcaster Alan Jones on 2GB – has attracted strident opposition from those who believe it cheapens the globally recognised icon and promotes gambling.

Prime Minister Scott Morrison backed Ms Berejiklian and called opponents of the promotion "precious".

In her first public comments since intervening, Ms Berejiklian defended her decision and said she was "absolutely confident" the display was "the right thing for Sydney".

In a column for the Herald, Mr V'landys said Racing NSW never intended to use the sails as a billboard for the barrier draw on Tuesday.

"We just wanted what other sports, and cultural events, had been afforded as a way to highlight to the world that Sydney is a seriously great place for events" he said.

"The idea was to incorporate a Sydney [and an Australian] iconic landmark in a way to showcase The Everest – the richest race in the world on turf – to a world audience and with an outcome that was beneficial to all parties, or so we believed."

But Mr V'landys defended using the sails, insisting it was to promote "a unique Sydney event" rather than gambling.

"The Opera House sails have been used to promote other events," he said. "Gambling is also conducted on these events, such as the Ashes and rugby union.

"The sails have also been used to promote the Mardi Gras and photos have been displayed on the sails for a Samsung phone promotion.

"It should also be highlighted that the construction of the Opera House was partly funded by the Opera House lottery. The rest was funded by the NSW taxpayer."

Mr V'landys said the promotion would be considerably less than the displays for other events.

"The actual promotion, which is a barrier draw, goes for just 10 minutes," he said. "The majority of the time is devoted to a light show, which has nothing to do with the event.

"The original proposal has been significantly wound back after negotiations. Firstly, the logo is now not included; the name of the horse is now not included; the actual race field is now not included; all that is left is the trophy, the colour of the jockey silks and the barrier the horse has drawn."

Speaking after visiting the Bathurst 1000 motor race, Mr Morrison said The Everest was one of the biggest events of the year and generated "massive opportunities" for the city and the state.

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

Mr Morrison, who was formerly managing director of Tourism Australia, said he would "put the Bathurst 1000 on the Harbour Bridge if I thought it was going to get more people there”.

“It’s just common sense and I don't know why people are getting so precious about it.

“Sometimes I think people have just got to have a bit of a lie down on this sort of stuff. They can get all very unctuous about it.”

Mr Morrison rejected suggestions The Everest promotion supported gambling.

“We're talking about an event that is one of the big money spinners for the state. It creates jobs. This isn't about advertising a packet of chips. This is about advertising one of the biggest events that NSW holds.

“Frankly, I thought it was a no-brainer. I can't work out what all the fuss is about.”

A petition circulated via Change.org in support of Ms Herron had gathered almost 120,000 signatures at the time of publication.

At a media conference about cyber bullying reforms, Ms Berejiklian denied she had caved in to pressure from Jones.

She said the approved design was the result of weeks of negotiations and the government had reached a compromise with Racing NSW after rejecting numerous earlier proposals.

"The version that is going to be displayed on Tuesday is much toned down from what the government was first presented with," she said.

"What we've arrived at [is] a compromise, I believe a good compromise under the circumstances and that's why the government proceeded.

"There'll be no logos, no names, the only words on there are actually the words of the trophy itself and that is consistent with what has happened in the past.

"I say to people, have a look on Tuesday before you judge it."

Ms Berejiklian said the "vast majority of the display is artistic" with three or four minutes that included the trophy image.

Among widespread criticism of the Premier's decision, Sydney lord mayor Clover Moore labelled the promotion "blatant commercialism" and the Australian Institute of Architects criticised what it called the exploitation of "perhaps the greatest building of the 20th century".

NSW chapter president Andrew Nimmo said the Opera House's world heritage listing meant a responsibility to treat the building with respect and dignity.

"We are disappointed that the NSW government has intervened and instructed [the Opera House], against their policy, to allow its sails to be lit up with commercially driven material," he said. "It is not an advertising billboard."

The Herald revealed two of Jones’ business partners in the horse racing industry have contenders in the race, while a horse part-owned by him had also vied for a spot.

State Labor transport spokeswoman Jodi McKay, who was tourism minister when the Opera House sails were first lit up for Vivid, hit out at the "simply shocking" way Jones spoke to Ms Heron on radio.

"I just found the comments and the way that Louise was treated was just abominable," she said.

"Anyone doing their job should not be in that situation where they're being attacked personally like that over a decision they've made which obviously is within the guidelines that are set."

Ms McKay said she supported events being advertised on the sails - "having colours and promoting like we've done with Mardi Gras and other events is appropriate" - but said there needed to be clear guidelines about what is and is not allowed to avoid the current confusion.

Asked whether it was concerned about the impact of the furore, race sponsor Tabcorp issued a statement saying it was "delighted to [be] partnering with Racing NSW and the Australian Turf Club" for the second Everest and was "looking forward to the barrier draw".