A top Cabinet Minister has warned that HS2 is a "killer whale" that could "rip the arm" off the next Prime Minister.
Chancellor of the Duchy of Lancaster Kit Malthouse said the controversial high speed rail project could spell trouble for Rishi Sunak or Liz Truss as they battle for the keys to No10.
The Government has already axed plans for the most eastern leg of the Y-shaped line, which would have gone to Leeds, triggering a furious backlash.
Ministers have also already ditched a 13-mile, £2bn stretch of track - the Golborne Link - which would have connected the HS2 line to the West Coast Main Line to Glasgow.
Mr Malthouse was promoted to the top Cabinet Office job after Boris Johnson was forced to perform a crisis reshuffle in the wake of mass resignations.
He told the Telegraph that the next PM faces "killer whales", which he explained were "the big projects that sit out there below the surface, waiting to breach above the waves and rip your arm off".
He contrasted those with "hornets" plaguing the Government - issues such as the cost-of-living crisis, strikes and NHS backlogs.
"The engine at the moment is actually pretty good, and my predecessors have built a pretty good engine," he said of the Cabinet Office.
"But it's one that is recovering from Covid. During the pandemic it was very focused on its Covid work. And dealing with that particular national international emergency was a huge moment for the Cabinet Office. And it did some remarkable stuff.
"But it is now time for us to shift off that kind of big uni-focal activity, and have a look at all this other stuff."
Mr Malthouse continued: "These are the big projects that sit out there below the surface, waiting to breach above the waves and rip your arm off. Big projects with big money involved, that often take quite a lot of sophisticated leadership and management.
"And we need to just make sure that we've got the risk assessed properly on that for a new prime minister."
He said that HS2 is a "big project and it's definitely on the list" of so-called "killer whales".
"HS2 is obviously making significant progress," he said.
"What I want is when a new prime minister comes in, that he or she is able to say to me Kit, what should I be worried about? That's the exercise that we're going through over the next four to six weeks."
A HS2 Ltd spokesperson said: "With over 350 construction sites active between London and Crewe, three giant tunnelling machines currently underground, and works started on our viaducts and stations, HS2 is on budget and making fantastic progress.
"Furthermore, the project is providing work for over 26,000 people, with tens of thousands more jobs supported through our wider supply chain, and more than 2,500 companies awarded HS2 contracts to date.
"HS2 is zero-carbon public transport that will play a vital part in the Government's ambitions to level-up the Midlands and North."
