The $1.2 billion Narromine to Narrabri (N2N) project has just received approval from the Australian Government Department of Climate Change, Energy, the Environment and Water.

The project is the Inland Rail's longest section, comprising over 300 kilometres of new track.

"Inland Rail will support the shift of more goods onto rail, meaning faster, more reliable freight; safer, less congested roads; and fewer emissions," Inland Rail pre-contracts director Rob Storey said

"Now that we have a full suite of approval conditions, the survey and investigation activities are critical inputs to the next stage of design and securing the land needed for the Narromine to Narrabri project corridor.

"Inland Rail acknowledges the important input from the community, local landowners and businesses during the approvals process and remains committed to working with stakeholders."

When complete, the new section of track will link the completed Parkes to Narromine and Narrabri to North Star Phase 1 projects and will be able to accommodate 1,800 metre double-stacked trains.

The massive project will involve the construction of 58 new bridges, 14 new viaducts, 51 new public level crossings and 630 culvert banks.

Member for Parkes Mark Coulton said the approval of the project was a key step to getting it back on track following a damning review of the project led by Dr Kerry Schott.

The report revealed multi-million-dollar cost blow-outs and other major problems such as delays, environmental challenges and inexperienced project managers. This led the federal government to reduce the scope of the project.

"This is a great project, but there has been a lot of uncertainty and unnecessary delay due to the actions of the Labor Government," Mr Coulton said.

"While this approval for the N2N project is a positive step, I continue to question the Government's commitment and understanding of the Inland Rail project. The Schott report reinforced that there is a need for this project to be completed.

"The NSW Government approved the N2N project 12 months ago; there has been no need to drag this out for as long as the Government has."

Mr Coulton said more than $290 million has been invested in local businesses through the Inland Rail project, with 1,860 people employed on each of the Parkes to Narromine and Narrabri to North Star stretches of track.

"It is vital the N2N project commences work as soon as possible so that the positive impacts on my electorate are not lost," he said.

"I will always defend the work that has already been done on the Inland Rail project; all those involved should be proud of what they've achieved.

"I again urge the Government to signal its commitment to this magnificent piece of infrastructure and provide certainty to residents in the Narromine to Narrabri section.

"It's time to get on with the job."