Nearly three-quarters of Canadians doubt Ottawa can keep its proposed Toronto-to-Quebec City high-speed rail project within budget, prompting renewed calls for Prime Minister Mark Carney to scrap the multibillion-dollar plan.A new Leger poll commissioned by the Canadian Taxpayers Federation (CTF) found 72% of respondents were either not very confident or not at all confident the federal government could deliver the Alto high-speed rail project within its estimated $60-billion to $90-billion price tag.Only 28% expressed some or strong confidence the project would remain within the government's projected costs.The findings come as the Parliamentary Budget Officer (PBO) estimates the proposed rail line could cost taxpayers as much as $113 billion, exceeding Ottawa's highest estimate by $23 billion.“Canadians know the Carney government’s cost estimate for high-speed rail is unrealistic,” said CTF Ontario director Noah Jarvis.“The project is unaffordable at the current budget and everyone knows it’s destined to go overbudget.”The federal government is planning a high-speed passenger rail network connecting Toronto and Quebec City, with service through major communities along the corridor.Ottawa has estimated construction costs at between $60 billion and $90 billion.However, the PBO's recently released assessment puts the potential price tag between $75 billion and $113 billion, raising questions about the project's affordability and the financial risks facing taxpayers.At the upper end, the independent budget watchdog's estimate is approximately 26% higher than the government's maximum projected cost.The PBO's figures also exclude the potential addition of an eighth station in Kingston, Ontario..According to the CTF, applying the PBO's estimated construction costs per kilometre suggests a Kingston stop could add as much as $6.7 billion to the project.That could push the combined upper-end estimate to nearly $120 billion if the additional stop were approved and the projected costs materialized.The Leger survey found concerns about potential cost overruns extended across age groups and genders, with majorities expressing doubts that the project could be completed within the government's stated budget.The CTF argues the federal government should abandon the project rather than expose taxpayers to additional spending and borrowing costs.“Canadians can’t afford a big rail boondoggle that will drive up government debt and interest charges for taxpayers,” Jarvis said.“Carney needs to save taxpayer money and cancel the Alto high-speed rail project.”The proposed Alto network is intended to improve passenger rail connections between Canada's two largest provinces and provide faster travel between major urban centres.Supporters of high-speed rail argue such projects can improve transportation capacity, reduce travel times and provide an alternative to highway and air travel.However, the CTF maintains the gap between Ottawa's original estimate and the PBO's projections demonstrates the financial uncertainty surrounding the proposal.The federation says the latest polling shows Canadians are skeptical the government can deliver the project at its advertised price.With the PBO projecting costs potentially reaching $113 billion before any additional Kingston stop, the CTF is urging Carney to cancel Alto before taxpayers face further financial commitments.