An Indigenous Sydney councillor has called for the Aboriginal flag to replace the NSW flag on the Sydney Harbour Bridge as criticism grows over the $25 million price tag to erect a third flagpole.

Outrage over the price tag revealed this month has attracted criticism from all sides, including local Indigenous stakeholders and the state's Premier.

At a press conference on Sunday, NSW Premier Dominic Perrottet was unable to provide an explanation on the figure when questioned on how the costs added up.

Sydney company Poseidon Poles and Flags has also reportedly quoted under $650,000 for the project, including replacing the two existing poles.

Speaking on 2GB radio Monday morning the Premier said there were structural issues which meant the installation was not a simple process.

"The advice that I've received has been that it's complex," Mr Perrottet said.

"There are heritage concerns, obviously all polls will need to be replaced.

"All three of them are the equivalent size of a six-storey building."

Metropolitan Local Aboriginal Land Council chairwoman and City of Sydney councillor Yvonne Weldon said while encouraged by the permanent additional of the Aboriginal flag, the bulk of the plans were baffling.

"It's very long overdue," she said.

"The fact that they have to spend money on it really puzzles me a little bit.

"I think you don't need necessarily the state flag and the national flag.

"It's quite easy to take one or the other down and put it (the Aboriginal flag) up."

Ms Weldon said the cost had led to online backlash towards the First Nations community.

"I don't know how much it costs to put the other flag poles up, but I'm sure we weren't whinging about it then," she said.

"Were people not concerned about that then, or is it only concern now that it's for Aboriginal people to be recognised in a meaningful way?"

Mr Perrottet said his preference was for all three flags to be flying but conceded the current plan "doesn't seem to pass the pub test".

The Premier said he would review the plans to ensure taxpayers got value for money.

"I don't want the cost to get in the way of what is an important decision that we've made as a government," he said.

"I accept that there are challenges with it, but it certainly shouldn't be costing the taxpayers $25 million.

"I will come back to you once I've interrogated this to a much greater degree in terms of costing."

Funding for the project came out of Tuesday's NSW State budget, which included $716m allocated towards First Nations concerns.

Ms Weldon said the State Government must ensure the $25m flagpole budget must not come out of any budget allocation towards Indigenous people.

It is hoped the Aboriginal flag will fly permanently on the bridge by the end of 2022.

https://nit.com.au/22-06-2022/3314/indigenous-leaders-simple-solution-to-baffling-sydney-harbour-bridge-aboriginal-flagpole-cost