Russia sharply reduced gas supplies to neighbouring Ukraine today after a row over unpaid bills and prices, raising the spectre of supply disruptions to the European Union.

Russia's state gas monopoly Gazprom said it would cut off gas supplies to Ukraine today after the two sides failed to reach an agreement on how much Ukraine will pay in 2009.

As Russia again threatens to cut Ukraine's gas supply, Sarah Arnott surveys a battleground of economics and power politics

In the hills above Yerevan stands Tsakhadzor, the old Soviet Olympic training complex. Five years ago it was an eerie place, the crumbling accommodation blocks and moss-covered swimming pools standing like a ruined Inca city, abandoned in haste after some long-forgotten catastrophe.

The struggle for control of BP's Russian joint venture TNK-BP has escalated into open warfare, with a restriction on working visas that could see some of the company's most senior expat staff sent home

Director general, CIPR

Peter Sutherland, the chairman of BP, has branded as "apocalyptic" predictions of $250 for a barrel oil from Gazprom, Russia's state-backed energy giant, as the tortuous negotiations between BP and its own Russian partner took yet another twist.

The chief executive of the world's largest energy company has issued the most dire warning yet about the soaring the price of oil, predicting that it will hit $250 per barrel "in the foreseeable future".

TNK-BP chief executive to be interrogated by Russian investigators over 'corporate tax evasion'

Gazprom plans to grow its UK market share by a factor of 10 within five years but has no near-term plans to buy Centrica, the chief of the UK business said.

The Russian premises of the oil giant BP were searched yesterday for the second time in recent months, prompting renewed fears of a campaign to pressure shareholders into selling their stakes to a state-controlled company. Additionally, the Russian Interior Ministry said it was investigating back-tax claims against two units linked to the company.

A sign of Russia's boom times is that Zenit St Petersburg, bankrolled by the energy giant Gazprom, plan to take up their entire 13,000 ticket allocation for Wednesday's Uefa Cup final against Rangers in Manchester. But unlike many other Russian teams, they will take the field without one black player. "They have always known the fans would be against it," says a Zenit hooligan to Marc Bennetts. An Englishman who has lived in Moscow for over a decade, speaks the language and is an avowed fan of Russian football, Bennetts has produced an engrossing, authoritative account of the game in his adopted country as it makes a growing mark in Europe. Yet he does not shy away from the endemic corruption, racism and hooliganism, including a hair-raising account of how one team manager hired gun-toting thugs to attack five of his own players, whom he suspected of taking bribes to throw games. More Russian roulette than the beautiful game at times, it seems.

Fresh doubts have surfaced about the security of BP's business in Russia after its subsidiary TNK-BP told nearly 150 workers not to go to work after Russian authorities warned that their visas were no longer valid.

Vladimir Putin, the outgoing president of Russia, stepped in yesterday to defuse a crisis that threatened to slash gas supplies to Europe after Gazprom, the state-owned oil giant, cut the flow to the Ukraine.