The UK receives hydroelectricity from Norway via a submarine interconnection cable that runs under the North Sea. However, water levels in southern Norway have been so low this year that the country’s government could put its own consumers ahead of international customers. Residents of the country’s capital, Oslo, have been told to take shorter showers and turn off the tap when brushing their teeth as its reservoirs have been depleted by dry weather across Europe. Oil and Energy Minister Terje Aasland told the Norwegian parliament on Monday that replenishing dams will be prioritized over power generation when levels fall below the seasonal average. The move is a blow to the UK, as well as countries such as Germany and the Netherlands, which rely on cheap Norwegian hydropower. A 450-mile link connects Blyth, Northumberland, with Kvilldal Power Station. The €1.6 billion North Sea Link cable, which was activated last October, can channel up to 1.4 gigawatts of electricity between the two countries when demand is high in the UK and domestic wind generation is low . This is enough to power around 5% of UK homes. Aasland said electricity production in southern Norway was down 18 percent from last year, and production in southwest Norway last week was the lowest seen this year so far. He said: “This has resulted in historically high electricity prices and a situation where, for the first time in many years, we cannot completely rule out a power rationing period in the spring. But our professional authorities stress that the likelihood of this happening is low.” Aasland said it was unlikely to hit Norwegian households this winter and supply disruptions would likely occur next April or May, mostly for businesses rather than consumers. The move could prove to be a test of European cross-border solidarity as Russia’s invasion of Ukraine puts pressure on energy supplies. Countries are scrambling to stock up on natural gas ahead of winter amid fears that Vladimir Putin’s regime could shut off natural gas to Europe. Subscribe to the Business Today daily email or follow Guardian Business on Twitter @BusinessDesk In the UK, Business Secretary Kwasi Kwarteng has moved to boost energy supplies as concerns grow that Britain could face high prices or even blackouts if gas supplies are diverted elsewhere. Consultancy Aurora Energy Research said a cut in Norway’s electricity exports could push wholesale energy prices even higher but was “unlikely” to threaten security of supply. Kit Malthouse, the chancellor of the Duchy of Lancaster, said on Monday that the government was preparing hospitals for possible fuel shortages. He told TalkTV: “We need to make sure that all those hospitals that need access to electricity have their standby generators properly maintained, have diesel tanks full of diesel that may be required. “The work they need to do to make sure they’re resilient in terms of power and energy has been done before we get to, say, November when winter starts.” Drax’s coal-fired plant in West Yorkshire and EDF’s West Burton A plant in Nottinghamshire have been put on standby for power supply as a contingency this winter. Aurora said that if the system operator, National Grid, called on their services “it would cause energy prices [in the UK] to increase, due to the higher cost of coal-fired power generation compared to hydropower imported from Norway.” The typical annual gas and electricity bill is already expected to reach £3,615 in October, according to consultancy Cornwall Insight. Analysts fear this could top £4,000 early next year. More than half of Britons are cutting back on gas and electricity use at home as the cost of living crisis worsens.