Rishi Sunak has become embroiled in a bitter row with regional politicians, the transport industry and members of his own party as he prepared to announce the cancellation of the multibillion high speed rail line to Manchester. The prime minister is set to call an emergency cabinet meeting on Tuesday at the Conservative party conference in Manchester, where ministers are expected to give their approval to the biggest infrastructure climbdown in a generation. As leaked details of the U-turn threatened to derail the conference, Sunak came under fire from politicians and business executives, who accused him of abandoning the government’s commitment to levelling up. Some of the most vocal criticism came from Andy Street, the Conservative mayor for the West Midlands, who told reporters the prime minister was in danger of “cancelling the future”. Speaking from the entrance of the hotel where Sunak is staying, Street said: “This has become a debate about Britain’s ability to do the tough stuff successfully, as previous generations of Britons certainly did. And of course now it’s become a debate about Britain’s credibility as a place to invest.” Henri Murison, the chief executive of the Northern Powerhouse Partnership, said: “It is madness to leave what was meant to be the UK’s flagship infrastructure project like this. Unless we can protect the hybrid bill, which is currently going through parliament and which authorises the tunnel between Manchester and Manchester airport, this means the end for Northern Powerhouse Rail and levelling up as a whole is finished.” The row added to what has been a difficult start to the conference for the prime minister, who also saw his predecessor Liz Truss steal the limelight during a packed fringe event at which she called for immediate and sweeping tax cuts. Conservative advisers are aware of how it will look to have the prime minister announce the cancellation of a train line to Manchester from a former train station in Manchester. However Sunak has been pushed into making a faster announcement than he had planned after speculation about the future of HS2 dominated the first day and a half of the conference. The prime minister has spent weeks re-examining the case for the project after costs ballooned to at least £71bn as measured in 2019 prices, and will frame his decision as evidence that he is willing to take unpopular decisions for the long-term interest of the country. During that process however he has failed to consult some of those at the heart of the project, including leaders of HS2 Ltd, the company that is in charge of implementing it. Sunak could even announce that the high-speed line will end on the outskirts of London, with trains stopping at Old Oak Common rather than six miles east at Euston, with some of the savings spent on alternative transport schemes for the north. Reports on Monday evening, however, suggested the line will terminate in Euston, although it was not immediately clear if that would be after Old Oak Common opens. Some in government have suggested using the money on an east-west rail link instead, although plans for a high-speed line between Liverpool and Hull depend on some of the HS2 infrastructure being in place first. Andy Burnham, the Labour mayor for Greater Manchester, said on Monday: “If you scrap HS2, you are scrapping the possibility of a new east-west line across the north of England any time soon. We will not accept vague commitments about improving east-west links – we really won’t – because people here have waited far too long for a functional railway and we are not going to sell our own residents down the river.” Darren Caplan, the chief executive of the Railway Industry Association, said: “This constant salami-slicing of the scheme betrays HS2’s original purpose to improve the UK’s connectivity and economy, while enabling added capacity to the classic network and helping the government deliver on its net zero targets. A decision to cancel would also send a terrible message about the UK’s ability to deliver major infrastructure projects to international investors.” Andy Bagnall, chief executive of Rail Partners, said scrapping the Manchester leg “will send a shock wave through the rail industry, its supply chain and all those with a stake in the project, including the northern communities it would have served”. The decision is part of a broader reset by Sunak as he looks to halt his party’s slide in the polls before a likely election next year. Last month he announced he was pushing back some of the government’s net zero commitments, including the deadline to phase out the sale of new petrol and diesel cars. That announcement appears to have helped the Tories narrow Labour’s poll lead, which now stands at about 16 percentage points. However, the HS2 decision threatens to prove more controversial, especially among northern voters who helped deliver the Conservative majority in 2019. Conservative ministers spent much of Monday trying to shore up support among their rightwing support base with a series of pledges to overturn regulations that do not really exist. Thérèse Coffey resurrected one of the oldest rows over Brussels red tape when she promised to cancel rules on “bendy bananas”. Mark Harper promised to stop local councils deciding how often residents can go to the shops, without being able to name a single council which is doing so. In one of the more substantial policy announcements, the chancellor Jeremy Hunt announced the government would reduce the size of the civil service by 66,000 to pre-pandemic levels. He did not say how long that process would take.