The debate over the true cost of Labor's Metronet transport plan will be settled before West Australians go to the polls.
After a day spent trading claim and counterclaim with Transport Minister Troy Buswell, Opposition Leader Mark McGowan relented late yesterday and committed to having his ambitious rail plan costed by Treasury before the March 9 election.
The backflip came after Mr Buswell released the advice from the Public Transport Authority that has formed the basis of the Liberals' claim that Metronet - which includes new rail lines to Ellenbrook, Perth Airport and circle lines through the northern and southern suburbs - will cost $6.4 billion.
Mr McGowan's team was unmoved by the revelations, sticking resolutely to its $3.8 billion price tag, claiming the PTA had costed a plan that was different from what it would build.
_The Weekend West _ can reveal internal Liberal Party polling shows Metronet has gained traction in the community but that a Liberal-Nationals Government would be returned by a narrow margin.
According to the polling, the Liberals would win Forrestfield from Labor, while Brendon Grylls would win the Pilbara and Wendy Duncan would take Kalgoorlie for the Nationals.
However, Labor would win Morley and Swan Hills from the Liberals and pick up Fremantle from independent Adele Carles.
If that scenario plays out, Labor would hold 27 seats - three short of Government - and the Nationals would increase their representation to six seats, entrenching their balance of power position.
The polling also suggests that Wanneroo is in danger of falling to Labor and that the ALP's Peter Watson may hang on in Albany.
It can also be revealed that credit ratings agencies are keeping a close eye on the parties' multi- billion-dollar election promises as former under-treasurer John Langoulant said neither Labor nor the Liberals had done enough work to establish if the benefits of their public transport pledges were worth the big price tags.
With Mr McGowan now satisfied that Mr Buswell had released all of the PTA's Metronet costings, which were done before it announced the fine detail of its plan during the election campaign, he said he would now submit the project to Treasury. "It is now incumbent upon the Liberal Party to submit both their MAX and airport rail line plans to Treasury to have them fully costed," he said.
Premier Colin Barnett said that if Labor submitted its Metronet costings to Treasury, he would accept the department's verdict.
The wild discrepancy in the parties' Metronet costings hinges on two engineering issues - whether or not Labor's plan requires the Midland line to be duplicated between Bayswater and Midland stations, and the extent to which Labor's airport line must be sunk as it swings south around Perth Airport's runways.
It is understood Under-Treasurer Tim Marney will test the engineering assumptions by seeking further information from Labor and Government agencies, including the PTA.