HS2 should continue to be built in full despite costs soaring to £88 billion, a review of the scheme has reportedly indicated.
A leaked early draft of the report seen by The Times stated that the high-speed railway could boost Manchester and Leeds more than London due to better connections on intercity routes.
The report has been welcomed by political leaders in the North West.
Connecting Britain, a coalition of business and cross-party political leaders, welcomed the findings while insisting that Northern Powerhouse Rail (NPR) - a plan to transform train services across the region - must be delivered at the same time as HS2.
Manchester City Council leader Sir Richard Leese said: "We welcome this apparent acknowledgement that HS2 will boost the North and begin to level up decades of under-investment in our regions.
"But we still don't expect the Oakervee review's final report until later this autumn and so in the meantime we will continue to present the case that HS2 and NPR need to be delivered together, in full."
It also claimed there are no "shovel-ready" alternative schemes to raise capacity on the existing railway, and "large ticket price rises" will be needed to discourage peak-time travel unless it is built.
But the review, led by former HS2 Ltd chairman Douglas Oakervee, warned that the project's latest cost estimate of £88 billion is expected to increase further.
HS2 was allocated £56 billion in 2015.
Phase 1 of HS2 is planned to run between London and Birmingham, with Phase 2 of the project running to Manchester by 2031.