ATHENS — From Athens in the east to London in the west, Europe is reeling from soaring energy costs that look set to rise even further following a decisive move by Ukraine today to halt Russian gas shipments.

A Ukrainian pipeline operator said Russian shipments through its Novopskov hub, in an area controlled by Moscow-backed separatists, would be cut beginning Wednesday. It said the hub handles about a third of Russian gas passing through Ukraine to Western Europe; Russia’s state-owned natural gas giant Gazprom put the figure at about a quarter. 

The move marks the first time natural gas supplies have been physically affected by the war that began in February and it may force Russia to shift flows of its gas through territory controlled by Ukraine to reach customers in Europe. Gazprom initially said it could not do that, but the Associated Press reported that preliminary flow data suggested higher rates moving through a second station in Ukrainian-controlled territory.

The operator said it was stopping the flow because of interference from “occupying forces,” including the apparent siphoning of gas. Russia could reroute shipments through Sudzha, a main hub in a northern part of the country controlled by Ukraine, it said. Yet a Gazprom spokesman, Sergei Kupriyanov, said that would be “technologically impossible” and questioned the reason given for the stoppage.

Whatever the reason, the stoppage is likely to exacerbate the turmoil in European energy markets already roiled by sometimes vocal splits over sanctions on Russian energy imports. In the latest wrinkle, Brussels dropped its proposed ban on EU tankers carrying Russian oil, with divisions forcing the bloc to water down its latest package of economic sanctions against Moscow, the Telegraph reported.

The EU’s president, Ursula von der Leyen, even flew to Budapest this week to meet with the Hungarian prime minister, Viktor Orban, in a last-ditch effort to persuade him to join in on a European Union-wide ban on Russian fossil fuels. She failed to do so. It is telling that Mr. Orban did not fly to Brussels for the hastily convened tête-à-tête, which Ms. von der Leyen weakly tried to paint as “helpful.”

Intensive lobbying from Greece —  which owns more than a quarter of the world’s oil tankers by capacity and is heavily reliant on its shipping business — is said to have led bureaucrats in Brussels to scrap plans for  rules that would have banned European tankers from carrying Russian crude oil anywhere in the world. That concession, the British newspaper reported, prompted accusations from diplomats that the U-turn undermined the sanctions and allowed EU vessels to divert Russian oil to India and China from Europe.

According to the Eurasia energy geopolitics senior lecturer at the University of Peloponnese in Greece, Thrassy Marketos, electricity prices are skyrocketing all over Europe. He blames this on “the kleptocracy of the global energy market,” which in his estimation “has made huge profits in the last two months of the war in Ukraine.”

Dr. Marketos told the Sun this situation “is indeed favoring the oligarchs supporting Putin’s regime in Russia.” He added that price increases have their origin in the war, “given that Ukraine is still a major transitory state of Russian oil and gas to Europe.”

Exhausted Greeks and Bristling Brits

Developments in Ukraine will keep the pressure up on already rising energy costs in Greece, particularly with supplies in jeopardy. Last week the Greek prime minister, Kyriakos Mitsotakis, promised new state support to shield households from rising electricity costs, saying the country was forced to act alone after its European Union partners failed to adopt a joint response to the problem. 

Mr. Mitsotakis reportedly said Greece would partially fund the program through a 90 percent tax on gains electricity producers have accumulated from the increase in power prices, which he attributed to gas price hikes as a result of the war in Ukraine.

“On this issue, Europe is showing itself — until now at least — to not live up to the circumstances,” Mr. Mitsotakis said in a televised address to the nation, adding, “I am not going to wait until the slow-moving European ship changes course.”

In Britain, the soaring cost of living is creating headaches from the halls of Westiminster to the aisles of popular supermarkets. Prime Minister Johnson came under pressure over the surge in prices facing British households during the Commons debate on the Queen’s Speech, which sets out the government’s legislative agenda, Sky News reported. In the speech itself Mr. Johnson said that he “can’t shield everyone from the cost-of-living crisis.”

How much of the crisis can be put down to the war in Ukraine is difficult to quantify, but consumer hardship in Britain is mounting. The chairman of Tesco’s, a grocery chain, reportedly said this week that shoppers are asking supermarket cashiers to stop scanning items when their basket’s total reaches $50 as households struggle to put food on the table due to the rising cost of living.