'Manipulating' supplies

Russia provides around 40 per cent of the gas imported by the EU, accounting for about a quarter of the bloc's overall gas consumption.

Mosocw  cut off its supply of gas to Ukraine on New Year's Day and has since accused Kiev of "stealing" Russian gas transiting Ukraine to clients in Europe.

Ukraine has denied this and has accused Russia of "manipulating" gas supplies.

The office of Viktor Yushchenko, Ukrainie's president, said that the EU is to send a delegation to the Ukrainian capital to discuss the country's deepening gas conflict with Russia.

In a statement, the Ukrainian presidency said the team would include Martin Riman, trade and industry minister of the Czech Republic, whose country currently holds the rotating bloc's presidency.

Matthias Ruete, the EU commission's chief transport and energy official, would also be in attendance, the statement said.

It said the mission was being undertaken "in line with the agreement reached by the Ukrainian delegation" that toured Europe last week.

Russia has urged the EU to send its own observers to monitor the flow of gas through Ukraine.

Court threat

Meanwhile, a Gazprom official has threatened to sue Ukraine over its gas transit contract.

Alexander Medvedev, the company's deputy chairman, said the gas giant would file documents this week with an arbitration court in Stockholm in a bid to force  Naftogaz, Ukraine's state energy company, to honour a contract for Russian gas that transits Ukraine on its way to European customers.

In Paris on a tour of European capitals to argue Gazprom's side of the dispute, Medvedev said that Ukraine had broken the transit contract.

He said Ukraine had no right to link the increase in gas supply prices that Gazprom is now asking for with an increase in the transit fee the Russians pay to send gas across Ukraine to the rest of Europe.