(Bloomberg) -- The UK government should rework plans for its high-speed rail network terminus in London amid spiralling costs, the budget watchdog said, a further setback for a project that’s already seen £2 billion spent on preliminary works.    

The National Audit Office wants the construction of the Euston station reviewed during the two-year pause for the project, as repeated changes and work interruptions have already escalated costs. Therefore, it was vital to “reassess the expectations,” the NAO added.

Originally designed to improve links between London, Birmingham, Manchester and Leeds, HS2 has faced long delays and concern over mounting costs and its environmental impact. Earlier this month, the government said it was halting construction at Euston station, as well as the Birmingham to Crewe leg due to an inflation-led cost overrun.

“The March 2023 announcement by the transport secretary pausing new construction work should now give DfT and HS2 Ltd the necessary time to put the HS2 Euston project on a more realistic and stable footing,” said Gareth Davies, the head of the NAO in the statement. 

The report said HS2 Ltd. has already spent around £500 million on Euston station as well as a further £1.5 billion on land purchases around the hub and other preparatory work. Between 2020 and 2022, the estimated cost of the work soared from £2.6 billion to £4.4 billion.

Billed as Europe’s biggest infrastructure project, plans have been pared back as the price tag has soared beyond initial estimates of £20 billion. The extension to Leeds was scrapped in 2021.

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