The flotation on the London Stock Exchange of Rosneft was seen in Moscow as an imprimateur of international approval for the new energy giant, built on the ruins of the Yukos empire. Not only did the Kremlin hope that a successful initial public offering would set an example to international investors of the attractiveness of Russian energy; it also hoped that a big take-up of Rosneft shares, at home and abroad, would quash criticism voiced by some investment analysts that the shares were “tainted” because of the Yukos connection.

There now seems no way that this connection can be overlooked. Whatever the High Court ruling on Monday, Rosneft investors know that the private oil company, formerly controlled by Mikhail Khodorkovsky who is now serving a long sentence in a Siberian labour camp, will continue to pursue the Kremlin in the courts.

The Rosneft IPO coincides with the G8 meeting in St Petersburg, at which energy security will be the main theme. Although this was the agenda chosen by the Kremlin, Mr Putin is likely to come under harsh criticism from his G8 partners for using energy as a political weapon and for the Kremlin’s determined attempts to renationalise its gas and oil resources by the back door.

Mr Putin is likely to be furious with Tony Blair over the threat of a High Court injunction. There is, however, little the Prime Minister can do to intervene in what is purely a commercial struggle.

Russians are expected to buy about 40 per cent of the Rosneft shares, making the London float an event of considerable importance within Russia. And although some foreign investors have been put off by warnings from investment analysts of the legal challenge by Yukos, there is likely to be a strong uptake of shares by foreign oil companies eager to keep in with the Kremlin.

Russia will use the cash raised from the stake sale to pay back a $7.5 billion (£4 billion) loan taken out last year, borrowed by the state-owned Rosneftegaz to buy additional shares in the gas monopoly Gazprom, thus increasing state control over the giant company. Any legal challenge that halts the sale of shares could therefore have a big impact on the Kremlin’s financial calculations, and seriously embarrass the state.

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