Ian Waters and John Doyle, from Unanderra company K&R Fabrications, started a petition calling for 100 per cent Australian steel to be used in projects after news the Port Kembla steelworks could close.

While no decision has been made, BlueScope has indicated the possibility of shuttering the Port Kembla plant if steelmaking costs were not reduced by at least $50 a tonne.

"BlueScope for some time has been reducing its workforce and trying to keep their costs down," Mr Waters said. "There's obviously a bit of a surge going on with that now. That's what sparked the petition, together with the news the state government sold the poles and wires and, on behalf of taxpayers, were going to spend that money on infrastructure projects."

After launching the petition about a month ago, it has attracted more than 10,000 signatures. The bulk of those have come from the Illawarra but Mr Waters said people as far as far away as Orange, Melbourne and even Perth have also signed.

Once a petition gets 10,000 signatures, it can compel a debate on the issue. Mr Waters said they planned to get 12,000 signatures to ensure all the signatories are accepted.

"Once we've got 12,000 we're going to present it to Gareth Ward, the member for Kiama and he's going to present it to the Parliament which will then force a debate in Parliament," Mr Waters said.

"We're not bring critical at all of the government - this government or any government. We're just asking them to change their procurement strategy for the future."

Mr Waters said calling for the NSW government to legislate for the use of 100 per cent Australian steel wasn't "groundbreaking" because this was already occurring in Victoria.

The Labor government has pledged to replace 50 level crossings with overpasses and underpasses using 100 per cent Australian steel.

Mr Waters said the 100 per cent target was not ambitious. "It's realistic and it's achievable," he said.

"The drama with any percentage less than 100 is there's always the opportunity for the people doing the work to say that they've got 50 per cent or 54 per cent or some number, but then to actually see the evidence, it's often very difficult to prove that.

"If the requirement is 100 per cent it's very simple as anyone can observe any piece of steel in the project and you can tell if it's Australian or not.

"Anything less that 100 per cent is difficult to measure."