Greece has warned that Russian strikes on Ukrainian infrastructure contributed to electricity prices more than doubling this summer in south-east Europe, underlining the vulnerabilities of EU energy markets.

Kyriakos Mitsotakis, the Greek prime minister, has called on Brussels to urgently tackle a “prolonged crisis” of capacity that has driven prices to such extreme levels that it requires an urgent “political response”.

In a letter to European Commission seen by the Financial Times, Mitsotakis said that electricity prices had risen in August from €60 per megawatt hour to €130 per MWh. He called on Ursula von der Leyen to use her second five-year term as commission president to “take up the task of pushing through more cross-border capacity” to avoid such spikes in future.