WA Labor's Metronet rail plan has been boosted by federal opposition leader Bill Shorten pledging federal funding and labelling it his number one infrastructure priority for Perth.

Metronet was the centrepiece of the state opposition’s 2013 election campaign, when the party estimated it would cost $3.8 billion, although the Liberal state government’s then-Treasurer Troy Buswell claimed it would cost $6.4 billion. Tim Marney, WA’s Under Treasurer at the time, estimated the project would cost about $500 million…