A Whitehall department says cash committed by the previous Tory administration was not allocated in its budget and so will not be taken forward.
The Department for Science, Innovation and Technology (DSIT) said the funding committed by the previous Conservative administration was not allocated in its budget and so will not proceed.
Some £300m already earmarked for AI Research Resource would continue as planned.
A DSIT spokesman said: “We are absolutely committed to building technology infrastructure that delivers growth and opportunity for people across the UK.
“This is essential to restore economic stability and deliver our national mission for growth.”
The Labour government said it would consider future investment in computer infrastructure following the development of its AI Opportunities Action Plan, which is being led by industry expert Matt Clifford.
He added: “If the UK doesn’t have national capability and also doesn’t have any tech giants, it’ll never be a significant player in AI and won’t reap the economic benefits.”
Andrew Griffith, the Conservatives’ shadow science, innovation and technology secretary, wrote in a post on social media site X, he said: “If Labour have lower ambitions for UK tech sector – or the new secretary of state cannot get the same level of support for DSIT from the chancellor – that’s up to them but no one should be fooled by Labour trying to blame their predecessors.
“We increased public spending on research to a record £20bn a year for 2024/25 and unlike Labour, we committed to increase that by a further 10% in our manifesto. AI and exascale compute were both beneficiaries of this increased funding.”
He added: “As a point of fact, at the time the election was called, ministers had been advised by officials that the department was likely to underspend its budget for the current financial year.”
The future of the exascale supercomputer project remains unclear, with the University of Edinburgh having already spent £31m on a new wing of its advanced computing facility, which was purpose-built to house the supercomputer.
It had expected to begin the first phase of installing it in 2025, according to the university’s website.
A university spokesperson said: “The University of Edinburgh has led the way in supercomputing within the UK for decades and is ready to work with the government to support the next phase of this technology in the UK, in order to unlock its benefits for industry, public services and society.”
It is understood the university’s principal and vice-chancellor, Professor Sir Peter Mathieson, is urgently seeking a meeting with the technology secretary.