Mayor of London Sadiq Khan has demanded “urgent clarification” from Rishi Sunak on how the construction of a new high-speed rail terminal in Euston will be funded, just days after the prime minister announced swingeing cuts to the line.

In a letter to Sunak, Khan said he had “serious concerns” regarding the HS2 project — particularly on how the government plans to find the £6.5 billion ($8 billion) required to complete the development around London Euston, the southern terminus of the new rail line.

After Sunak appeared to withdraw public funding for the Euston redevelopment earlier this week, Khan said it was “wishful thinking” to assume that the private sector would step in at a time when Britain’s economy is expected to stagnate.

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At the Conservative Party conference on Wednesday, Sunak scrapped the long-awaited northern leg of HS2 — which had been a key pillar of the Tories’ ‘levelling-up’ agenda to spread prosperity outside of London. Instead of extending to Manchester, it will now only stretch as far as the West Midlands city of Birmingham.

At the other end of the line, Sunak appeared to allay concerns that the southern terminus would be Old Oak Common, a station six miles outside of central London, as he confirmed it would continue into Euston.

But he also revealed that the 60-acre site where Euston is located, and where new homes, businesses and community facilities were expected to be constructed as part of the HS2 project, will now no longer be managed by HS2.

Instead, Sunak unveiled a “new Euston development zone,” implying that the area’s redevelopment will now be funded by the private sector.

“The private sector will be expected to cover the cost of the terminus, potentially through the establishment of a Development Corporation,” Khan said in his letter to Sunak.

“Given current challenges in the British economy, asserting that the £6.5 billion cost of a terminus at Euston and potentially more for the tunnel link to Old Oak Common will be covered by the private sector seems wishful thinking.”

Khan demanded to know whether the government would act as a “funder of last resort” if private money was not forthcoming, and asked whether it was still the plan to connect Euston with the nearby Euston Square Underground station.

He also questioned how the 10,000 homes which Sunak claimed the Euston site would now hold — far more than previously expected — would be delivered alongside the employment space promised.

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