London, Jul 14 (IANS): European consumers could face the prospect of energy rationing this winter as costs continue to soar amid the risk of Russia cutting off gas supplies, Shells chief executive has said, the media reported.

"It will be a really tough winter in Europe," said Ben van Beurden, speaking at the Aurora spring conference in Oxford on Thursday, The Guardian reported.

"We will all face very significant escalation in energy prices. In the worst case, Europe will need to ration its energy consumption."

Factors being blamed for the continuing surge in wholesale energy prices include ongoing uncertainty regarding Russian gas flows into continental Europe, as well as more recent concerns such as the halted strike by Norwegian gas workers, and the UK's continued reliance on energy imports.

Van Beurden said there was "no way of telling" whether Russia would restart gas supplies into Europe via the Nord Stream 1 pipeline after maintenance started on Monday. It is due to conclude on 21 July, The Guardian reported.

"Putin has surprised quite a few of us," he said, adding, "I feel disappointed by the outcomes. He has also shown that he better be taken seriously when he makes threats... For a long time we thought it was not in Russia's interest to cut off Russia's largest market. He is able and willing to weaponise supplies."

Asked about the race to become the next UK prime minister, Van Beurden said: "I hope there is no backtracking from net zero ambitions. There is a lot of popular opinion out there that is sometimes not helpful."