The HS2 rail project, which has been beset by severe delays and soaring costs, has been branded as “unachievable” by the government’s infrastructure watchdog. Having analysed plans for the construction of the first two phases of the high-speed line, from London to Birmingham and then on to Crewe, the Infrastructure and Projects Authority said the project was not, in its view, deliverable in its current form. The IPA sits at the heart of government, reporting to the Cabinet Office and the Treasury, and its finding will be seized on by campaigners. Many wildlife groups and people living in the areas affected have been opposed to the scheme from the start. Huge swathes of the countryside have been destroyed by its construction. A “red” rating was assigned to the plans for the construction of the first two phases. This means that “successful delivery of the project appears to be unachievable”, the IPA said in its annual report on big projects. It added: “There are major issues with project definition, schedule, budget, quality and/or benefits delivery, which at this stage do not appear to be manageable or resolvable. The project may need rescoping and/or its overall viability reassessed.” The Labour peer Tony Berkeley, who has been a vocal critic of HS2, said on Sunday: “It should be cancelled tomorrow. This is the Treasury’s own report telling them that the scheme is unachievable. What more evidence do they need?” He added: “Everyone knows the money would be so much better spent on improving the existing rail infrastructure – particularly Northern Rail. Someone just needs to take the decision.” Christian Wolmar, the transport writer and broadcaster, said the most worrying aspect of the report was that it suggested the government had no idea how to resolve the scheme’s problems. Joe Rukin, the founder of the Stop HS2 campaign group, has described the project as an “unmitigated disaster from start to finish”. “It is massively environmentally damaging, prohibitively expensive, unwanted, unloved and unneeded,” he said before the IPA report came out. “It only exists because of hard lobbying from the construction industry, who wanted to build the most expensive railway in world history.” HS2 was initially scheduled to open in 2026 but is now projected to open between 2029 and 2033 because of construction difficulties and rising costs. A budget of £55.7bn for the whole project was set in 2015 and the target cost, excluding the eastern leg from the West Midlands to the east Midlands, has risen to between £53bn and £61bn at 2019 prices. The transport secretary, Mark Harper, announced in March that work at Euston would be paused for two years as costs had ballooned to £4.8bn, compared with an initial budget of £2.6bn. This month, HS2’s chief executive, Mark Thurston, announced his resignation after six and a half years of leading the government-owned company. The announcement came as phase 1 of the project between London and Birmingham was at peak construction, with major work taking place at more than 350 sites. The Department for Transport has been under pressure to find cost savings on the project as soaring inflation means the cost of raw materials has increased significantly. A DfT spokesperson said: “Spades are already in the ground on HS2, with 350 construction sites, over £20bn invested to date and supporting over 28,500 jobs. We remain committed to delivering HS2 in the most cost-effective way for taxpayers. “HS2 will bring transformational benefits for generations to come, improving connections and helping grow the economy.”