German consumers could face a tripling of gas prices in the coming months after Russia’s throttling of deliveries to Europe, a senior energy official has said.

Moscow reduced the flow of gas through the Nord Stream 1 pipeline by 40% last week, citing technical reasons that Berlin dismisses as a pretext, prompting a four- to sixfold rise in market prices, said the head of Germany’s federal network agency, Klaus Müller.

Such “enormous leaps in price” were unlikely to be passed down entirely to consumers, Müller said, but German citizens had to brace themselves for dramatically rising costs. “A doubling or tripling is possible,” he told the public broadcaster ARD.

He said the rising costs now showing up on people’s energy bills were the result of higher prices on the gas market last autumn.

The German economic ministry announced the second of three energy emergency plan phases on Thursday, warning of a high risk of long-term supply shortages as a result of Russia systematically choking off gas deliveries.