At least 1,000 protestors have staged a rally in Perth and marched on mining offices to demand more jobs for local workers.
"We're workers united, we'll never be defeated," they chanted.
Members from a number of unions, including the construction, maritime and electrical unions joined the protest against the Federal Government's enterprise migration agreements.
The EMAs will allow companies in the resources sector to use foreign workers on large projects such as Gina Rinehart's Roy Hill iron ore project.
The rally was held outside state Parliament before the protesters marched to Hancock Prospecting, Ms Rinehart's offices in West Perth.
Yesterday, the CFMEU said the boom needed to be used to train local workers.
The state opposition also said it would guarantee more jobs for local workers and contracts for local companies if it wins the next election.
Labor says it will introduce legislation to make sure major mining projects in the state award engineering, design, fabrication and manufacturing contracts to local companies.
Opposition Leader Mark McGowan says the policy will also require resources projects to employ local workers in the manufacturing sector before foreign workers are sought.
He says West Australians should be getting jobs ahead of foreign workers.
"We believe in maximising the benefits of the mining oil and gas industries here in WA for local people, for local businesses," he said.
"It's very important that we have a commitment from government that ensures that our fabrication workshops, our working people, are the beneficiaries of the state's success." If the work is not awarded to local contractors, companies must show why they are sending the work overseas or hiring foreign workers.
The Commerce and Finance Minister, Simon O'Brien, has said such legislation would be a waste of time.
"Look, all the legislation that the Labor party is proposing is just going to create more red tape and discourage business activity," he said.
"We've been getting on with real action; the runs are on the board, you know there's $20 billion of resources contracts gone to local companies since July." Mr O'Brien says with so many contracts already underway, there is no need for the legislation.
"In fact, under the West Australian Government this state has created five times as many jobs as the rest of Australia put together; that's real action and real policy," he said.
"So, I don't think the new Labor bill, which has already been rejected once by the Parliament, has got much to offer at all."