Arkady Dvorkovich MARRAKESH, Morocco, Oct 31 (Reuters) - A standoff between Ukrainian political forces ahead of a presidential election poses risks for Russian gas supplies to Europe, a Kremlin aide said on Saturday.

Russia cut gas supplies to Western Europe across Ukraine in January 2006 and again in January this year during a row with its ex-Soviet neighbour over gas prices and payments, disrupting supplies to EU customers in the dead of winter.

Russian Prime Minister Vladimir Putin said on Friday that Ukrainian President Viktor Yushchenko risked provoking a new gas crisis, after a telephone conversation with Ukrainian Prime Minister Yulia Tymoshenko, Yushchenko's main political foe and a frontrunner in a Jan. 17 presidential election.

"The situation is risky because of the election campaign taking place in Ukraine," Arkady Dvorkovich, the Kremlin's top economic adviser, told Reuters on the sidelines of the World Policy Conference in the Moroccan city of Marrakesh.

Russia's Gazprom, the world's biggest natural gas company, supplies a quarter of the European Union's gas, most of it through pipelines across Ukraine.

The Russian warnings raise the spectre of a new gas dispute, even though diplomats say Russia may be wary of sparking a row with Kiev on the eve of a vote which Moscow hopes will bring a more pro-Russian president, possibly Tymoshenko, to power.

Yushchenko came to power on the back of the 2004 "Orange Revolution" protests against a Moscow-backed candidate.

Russian President Dmitry Medvedev ruled out in August any improvement in relations with Ukraine under its current leader.

"We believe that as soon as this political process is completed, the sooner we will be able to get a solution," Dvorkovich said.

He said the European Union should help Russia create binding mechanisms for conflict resolution and to guarantee payments.