Microsoft has terminated its involvement in the £2bn AI data centre that Nscale is developing at Loughton in Essex, according to BBC News, which understands the company had committed to fund a supercomputer at the site. The Guardian reports that Microsoft was the project's expected anchor tenant and its only publicly announced customer, and that it informed Nscale of the decision after the site's power connection was pushed back. Microsoft declined to comment, the BBC said.
The trigger is electricity, not demand. UK Power Networks, which owns and maintains the grid across London and the south-east of England, has told Nscale it cannot supply enough power to the Loughton site until the early to mid-2030s, the Guardian reported earlier this month. The BBC's account puts the same message more bluntly: the data centre had been due to receive its power supply at the end of the year, but Nscale was told this would not happen until the 2030s. Nscale described the problem to the BBC as an "unfortunate London-wide grid issue".
A flagship project loses its anchor
The Loughton scheme was not a marginal development. When Nscale announced it in 2025, it pledged £2bn to build and open what the BBC describes as a pioneering facility, and the Guardian notes that Keir Starmer's government highlighted it when launching the UK's AI strategy that year, calling it the "largest UK sovereign AI datacentre". The site is expected to create 250 permanent jobs when it eventually opens, according to the BBC. As recently as last month, Microsoft said some of the $30bn (£22bn) it is investing in the UK would go towards funding the Loughton supercomputer, the BBC reported. The project had already drawn scrutiny. The Guardian revealed in March that the location was still an operational scaffolding yard, and it reports that Nscale has since cleared the site. The power constraint is a more fundamental problem than site preparation: it determines whether the facility can run at all, and on what timetable. Nscale insists the project survives. "We remain committed to both the Loughton project and the UK and we are exploring alternative power sources for the site, in addition to other expansion sites in the UK," a spokesperson told the BBC, adding that its relationship with Microsoft "remains strong and long-term". The Guardian reports that Nscale is investigating whether it can generate power onsite and whether the connection process can be accelerated. The two companies continue to work together on projects in Norway, Portugal and the United States, according to the BBC, and the Guardian reports Microsoft remains on board for Nscale's Norwegian project.Why the grid, not the customer, is the constraint
The sequence matters for anyone weighing UK data centre sites. Microsoft's commitment was announced in September; the grid warning surfaced in early October; the withdrawal followed within weeks. The commercial decision tracked the infrastructure timetable rather than any visible change in AI demand. That is the signal worth extracting: where connection dates slip by the better part of a decade, an anchor tenant's commitment is only as durable as the power contract behind it. The Guardian frames the wider stakes. Nscale, backed by tech companies including Nvidia, has positioned itself as Britain's "sovereign" datacentre provider and is aiming to float on Wall Street this year at a potential valuation of $35bn (£26bn). Its board includes the former UK deputy prime minister Nick Clegg and the former Meta chief operating officer Sheryl Sandberg; the Guardian reports Clegg holds a 0.25% stake that could be worth $88m at that valuation. The paper also notes a growing chorus of voices suggesting neoclouds may be a vulnerability in the broader AI economy as delays pile up across partners, and that a postponed initial public offering could bring those questions into sharper focus.Commercial impact
The immediate commercial effect falls on Nscale, which must now source power, and potentially onsite generation, for a site that has lost the customer underpinning its economics. For Microsoft, the decision is a reallocation rather than a retreat from the UK: its $30bn UK commitment stands, per the BBC, and its other Nscale projects overseas continue. For the UK government, the loss is reputational as much as industrial. The Loughton project was named in its 2025 AI strategy as the country's largest sovereign AI datacentre, and the Guardian notes that the strategy leaned heavily on two Nvidia-backed companies, Nscale and the US firm CoreWeave. For operators and investors assessing UK sites, the practical lesson is that grid connection timelines and energy pricing now sit alongside land and capital as gating factors. The Guardian's report that the failure to find a quick fix "underlines how much energy has become a hindrance to datacentre development" is the clearest statement of the constraint in the supplied reporting.Risks and unknowns
Several questions remain open. It is not known whether Nscale can secure alternative power at a scale and price that makes the Loughton site viable, or whether onsite generation is permitted and economic there. The BBC reports the site is expected to create 250 permanent jobs when it eventually opens, but no revised opening date has been given. Whether the withdrawal affects Nscale's planned flotation, and on what terms, is unresolved; the Guardian presents the valuation and the delay risk as context rather than confirmed outcomes. Microsoft has not commented publicly, so its reasoning is inferred from the timing of the grid warning rather than stated. And while Nscale calls the problem a London-wide grid issue, the supplied reporting does not establish how many other projects face comparable connection delays.FY Outlook
The next observable milestones are whether Nscale names an alternative power source or a revised connection date, and whether its flotation proceeds on the timeline and valuation the Guardian reported. A second test is whether other UK AI infrastructure projects disclose similar grid constraints; if they do, the Loughton case becomes a template rather than an outlier. The government's sovereign AI strategy, built around Nscale and CoreWeave, now carries a visible execution risk that investors will price. The demand case for UK AI capacity is not in question in this reporting. The ability to power it is.Sources and References
- Microsoft pulls out of UK's largest AI data centre — BBC News (bbc.co.uk)
- Microsoft pulls out of AI datacentre project in Essex over power supply concerns — The Guardian (theguardian.com)
