Gazprom’s uncompromising statement came in response to Ms Tymoshenko’s announcement that the deal struck between Kiev and Moscow at the start of 2006 would probably be reviewed by her incoming government. This deal sees Ukraine pay an increased amount for Russian gas imports, although much of Ukraine’s gas in reality comes from Turkmenistan under a complex set of trading agreements.

The contract between Ukraine and the Russian gas giant was only sealed after supplies to the former Soviet stake were temporarily suspended. In wording that leaves little doubt that such measures could be repeated by the Russians, Gazprom spokesman Sergei Kupriyanov said Ms Tymoshenko’s threats may lead to a new gas crisis.

We believe that Yulia Tymoshenko’s words again prove that Ukraine is regrettably the weak link in the chain of Russia’s gas supplies to Europe, he was quoted as saying by the RIA Novosti agency.

Gazprom’s stance is likely to trigger further anxiety in the EU, which has enjoyed an uneasy peace with Russia since the turn of the year. The EU is adamant that it needs to diversify its supplies of energy, while Gazprom – and by extension the Kremlin – is asking Europe for ‘security of demand’. Indeed, Gazprom is actively increasing its presence in the European gas sector, and on June 22 it purchased Pennine Natural Gas, a small supplier of business customers based in northern England.