Christmas wouldn't be Christmas without a gas row, and this year's Russia-Ukraine double act features a supporting role for the presidential elections in Kiev.
Ukraine's Naftogaz promised last week that no crisis is looming, RIA Novosti reported, insisting it had been paying Russia on schedule.
But Kiev's National Security Council published a report claiming that a Russia-EU pact intended to prevent supplies to Europe being cut was biased against Ukraine.
Naftogaz said this was "destabilising", and blamed President Viktor Yushchenko for stirring up problems.
Yushchenko promptly responded by claiming Prime Minister Yulia Tymoshenko was conspiring to bankrupt Naftogaz and betray Ukraine's national interests, and urging a "drastic review" of the current 10-year gas contract.
President Dmitry Medvedev in turn dismissed that as "totally irresponsible", adding that Europe would have all the gas it needed unless Ukraine failed to pay up.