WA Labor say their Metronet rail system will create almost 4000 jobs in Perth, if they win the state election.
Labor leader Mark McGowan said the jobs would be created directly or in "associated supply businesses during its construction phase".
"Metronet will require civil construction work including 75 kilometres of track work, construction of new stations and bridges, park and ride facilities, and associated earthworks," he said.
"Building the rail system will also require the installation of the overhead power systems, signalling systems, as well as ballast and sleepers.
"Based on job creation figures for rail projects elsewhere in Australia, Metronet is estimated to create at least 2000 jobs during its construction.
"These jobs will be created over an eight year period through Metronet's priority program, which includes building the Perth Airport line, Ellenbrook line, North Circle line, sections of the South Circle line and the Circle Freeway."
Another 1900 jobs are predicted to come from businesses supplying the project with concrete, steel, pylons, hardware and other materials.
Mr McGowan said WA Labor would seek to maximise the amount of local companies involved in the project and ensure that as much work as possible would be kept within the Western Australian economy.
The announcement came after Mr McGowan conceded details of the proposed Metronet would start talks with the Treasury about the cost of the project after the state's transport bosses estimated the cost would be double Labor's $3.8million price tag.