Labor leader Mark McGowan has claimed almost 4000 jobs would be created by his Metronet rail plan.
At an announcement this morning, Mr McGowan said an estimated 3900 jobs would be created both directly and indirectly from the project.
The announcement comes after the Opposition Leader committed to having the plan costed by Treasury before the March 9 election
He told reporters today the project was important for "job creating" in the State.
"Building a huge improvement to Western Australia's rail network and a huge improvement to our road network by creating the circle freeway will mean many jobs in construction and also in the supply industries to create Metronet."
"It will provide ongoing jobs, and what's more it will help business in the State."
Mr McGowan said Labor wanted to help the business community by fixing congestion "once and for all".
"The Chamber of Commerce and Industry, the RAC all estimate that congestion costs business money in Western Australia," he said.
"The CCI estimated that the median cost per business in Western Australia of congestion is $20,000."