Speaking at Labour’s economic conference in Liverpool, he said the new “High Speed 3” rail link would transform the economy of northern England, creating 850,000 additional jobs by 2050.
Mr McDonnell said the plan was part of a wider commitment by Labour to close the investment “gap” between the South and North of England.
However, the Conservatives warned that Labour’s borrowing plans would “crash” the economy, threatening jobs and infrastructure investment.
The shadow chancellor insisted Labour would reverse the “underinvestment, delays and a lack of real commitment from Whitehall” which had blighted the economic prospects for the North under the Tories.
“Labour is absolutely committed to delivering HS3, a Crossrail for the North, starting right here in Liverpool and connecting the great cities of the north of England,” he said.
“It’s at least a £10 billion commitment from Labour to invest in the North.
“It means the journey from Manchester to Leeds will take just 25 minutes, instead of close to an hour. Or you could get from Liverpool to Manchester in 25 minutes.
“Crossrail for the North will become the foundations for a transformed northern economy.”
Mr McDonnell’s intervention comes at a time when Labour is under pressure from Ukip in its traditional heartlands in the North and Midlands, many of which voted strongly for Brexit in last year’s referendum
Under current Conservative plans, he said, London was set to receive twice the level of public investment per head than the North, an imbalance they would redress through a “Barnett Formula for the North” - a reference to the mechanism for distributing government support for Scotland, Wales and Northern Ireland.
Labour, he said, would legislate to require ministers to audit their regional capital spend against economic need, and report to Parliament when the investment imbalances are “excessive”.
A Conservative spokesman said: “Labour’s policy to borrow half a trillion pounds would crash our economy and threaten jobs and infrastructure.”
Mr McDonnell, however, argued that Labour was simply seeking to end the unfairness of the past.
“The next Labour government will shift the balance of power and wealth away from a few gilded places in the South East and back into the rest of country,” he said.
“If we are to face the world after Brexit, it means every part of our country should be prepared. We have to put an end to the Whitehall view that what’s good for the City of London is good for the country as a whole. It’s time for the rest of the country to get a look-in.”