The mayor of Greater Manchester, Andy Burnham, has said Manchester should have an underground railway, as the cost of the delayed Crossrail project in London swelled to £17.6bn.

Burnham proposed a “Crossrail for Manchester-type scenario” where new railway lines would be built under central Manchester to help people get across the increasingly gridlocked city.

He made the remarks at an event about the future of rail in the north of England on Friday, as MPs in Westminster lambasted Crossrail’s delays and ballooning costs.

A report from the public accounts committee said Crossrail – which connects Reading in Berkshire with Shenfield in Essex through central London via 26 miles of new tunnels – is now expected to be delivered up to two years behind schedule and £2.8bn over budget.

After London, Manchester has the worst road congestion in England, according to the National Infrastructure Commission, and Burnham believes creating a tube system under the city could be part of the solution.

Burnham made the uncosted proposal as he pointed out that HS2, the new high-speed line from London that is supported by the Tory government and Labour, would run underground in the capital and its leafy suburbs – including for 21.6km (13.4 miles) under fields in the Chilterns – yet would bulldoze through central Manchester and large swathes of the north of England.

Current plans for HS2 envisage the new line tunnelling under eight miles of Greater Manchester from Manchester airport before emerging above ground at Manchester Piccadilly. Platforms will be 415 metres long, taking up valuable real estate. The station would expand further should Northern Powerhouse Rail – a new east-west link across the Pennines – get built.

Leaders in the north say an integrated underground option at Piccadilly could add £4bn to the Greater Manchester economy by 2035, while building above ground would “result in a sprawling train station in the heart of Manchester, slashing prime regeneration space”. Burnham said the result would turn “half of central Manchester into a railway station”.

In London, Euston station will be remodelled vertically, with 11 underground platforms for HS2.

“The government always seems to run out of money by the time they reach the north,” said Burnham, who hopes to influence the design of the Manchester leg, which is not yet guaranteed to be built.

He blamed London-centric decisionmakers for the Manchester station plans, which did not take account of future land values in the rapidly developing city. “Why are they trying to build HS2 on the surface here? The only answer I can give you is: because they can.”

Earlier this week, MPs overwhelmingly voted to build HS2 as far as Crewe, considered the gateway to the north of England.

But the future of the rest of the line is far from guaranteed. Boris Johnson, the frontrunner to become the next prime minister, has drawn up plans for an independent review of HS2 if he enters Downing Street as expected next week.

Luke Raikes, a senior research fellow at IPPR North, which hosted Friday’s event, said Burnham and other local leaders should have more say in transport planning: “An underground network may well be part of the solution for Greater Manchester, but regardless of which is the right option, the decisions about such investments should be made by accountable local politicians within Greater Manchester, not by remote officials in London.

“The evidence shows that central government does not invest strategically across the country, and that local areas are much better placed to make these decisions.”