NSW Premier Gladys Berejiklian has refused to rule out using the Sydney Opera House to promote other events after a huge backlash against the plan to project details of a horse race on the iconic building.

Protesters disrupted last night’s six-minute light show to promote The Everest on the heritage-listed building’s sails with torches and lasers at 7.40pm.

They later also targeted broadcaster Alan Jones’ luxury Circular Quay apartment with the lights.

The radio broadcaster had become a central figure on the row, which escalated this week and saw 235,000 sign an online petition presented to the NSW Government against using the building as 'a promotional billboard.'

But when asked if she would do it again, Berejiklian told the Today Show she didn’t want the state to ‘fall behind’ in tourism.

“Obviously we are always about supporting events. I hear loudly what people have said about the Opera House,” she said.

At 7.40pm when the famous sails were first lit up, people lining the building's forecourt also began to shine beams of light from torches onto the images in the hopes of obscuring the message. (9NEWS)

Protesters have targeted the planned projection of The Everest horse race colours and numbers onto the sails of the Sydney Opera House. (9NEWS)

“The Opera House guidelines have from time to time been amended, whether it's for other sporting events or other causes. The guidelines have always been stretched in the part and the commercialisation of the Opera House has always been there.

“I hear what people have said about what they want to see the Opera House used for and what they don't want to see it used for.

“As Premier of NSW have to balance those decisions. I don't want NSW to fall behind because other cities and states are promoting these events. These are issues that we take on board.”

Estimates put last night’s crowd as high as 3000, including many onlookers.

Some shouted ‘shame on you’ as they shone torches and other light sources at the building.

The $13 million, 1200-metre sprint at Randwick makes The Everest Australia's richest horse race and the biggest on turf in the world.

It falls in the middle of Melbourne's marquee Spring Racing Carnival, a strategic move by Racing NSW who have ambitions to drag money and attention from Victoria.

Fixed odds betting on the race was suspended yesterday afternoon until the barrier draw event, due to risks of a security breach.

Despite the numbers of beams coming from the ground, the strength of the imaging shone through. (9NEWS)

Racing NSW chief executive Peter V'landys claimed he and other staff members had received death threats.

The premier added she wanted to make it clear the move to go ahead was the government’s decision after being accused of ‘caving in’ to Jones’ demands.