Riverina MP Michael McCormack said the government had already started on a 10-year roadmap for upgrading the highway, beginning with the Parkes Bypass.

Opposition infrastructure, transport and regional development spokeswoman Catherine King said Senate Estimates last week revealed that funding would not flow until at least 2024-25.

"We know from Senate Estimates this week that funding for Newell Highway upgrades does not commence until 2024-25," Ms King said.

"Michael McCormack needs to actually get to work and deliver upgrades to the Newell Highway.

"The five year funding delay shows Michael McCormack's infrastructure program is a political document, not an economic plan.

"It is time the Michael McCormack got to work on a real plan for infrastructure to create jobs and improve productivity."

The Newell Highway Corridor Strategy was commissioned by the government in January and received $400 million in the May budget.

Mr McCormack said the strategy would deliver "an evidence-based, 10-year investment roadmap" that would "ensure the corridor serves the needs of the freight industry and regional communities well into the future".

"The Australian and NSW governments are working together to progress upgrades, drawing on the strategy's key findings," he said.

"We are already investing in the Newell Highway corridor, with planning well under way for the Parkes Bypass. The bypass will reduce congestion and delays caused by two rail level crossings and four intersections, which are difficult for heavy vehicles to navigate.

"Under the Roads of Strategic Importance initiative, a further $81 million has been committed to Stage 2 of the Mungle Back Creek to Boggabilla project, on which construction is expected to begin early next year."