Cash-strapped Ukraine may be unable to pay its gas bills in the coming winter, the chairman of Gazprom, the Russian gas monopoly has warned, raising fears of a repeat of last winter’s European gas crisis.

Alexei Miller said that while Naftogaz, the Ukrainian state gas company, had said it could meet its bills until the end of the year it was unclear what would happen in January, when Ukraine is due to hold hotly-contested presidential elections.