MINSK, Belarus (AP) — The Belarusian parliament on Tuesday decided to set the ex-Soviet nation's next presidential election for December, marking the start of a campaign that neighboring Russia will likely try to influence.

Belarus' fractured opposition has failed to agree on a single candidate to challenge President Alexander Lukashenko, who has ruled Belarus with an iron hand since 1994, stifling dissent and free media.

Lukashenko, however, is now facing a new challenge in the Dec. 19 election — a widening rift with Belarus' main sponsor, Russia.

Russia has a union agreement with Belarus and provided generous subsidies to help keep Belarus' Soviet-style economy afloat. It also shielded Lukashenko from international criticism over previous elections which international observers saw as fraudulent.

But Lukashenko's relations with Moscow have turned sour amid economic and political disputes, spelling potential problems for his re-election bid.

"Open confrontation between Lukashenko and the Kremlin could make it more difficult for Lukashenko to win the vote this time," said Alexander Klaskovsky, an independent Minsk-based political analyst.

Russia in June partially cut natural gas supplies to Belarus for three days over its debt for previous deliveries, finally forcing its neighbor to pay. Moscow also has rejected Lukashenko's push for lower duties for Russian oil supplies to Belarus under a customs union between the neighbors.

Klaskovsky and other analysts said that public discontent over rising consumer prices could erode Lukashenko's support base and affect the vote.

In addition to that, Russia's Kremlin-controlled television stations recently have run several documentaries containing fierce criticism of Lukashenko and exposing his alleged abuses — the propaganda barrage that is likely to intensify in the coming months.

Russia hasn't yet cast its support behind any of the Belarusian opposition leaders, but observers expect the Kremlin to make its preferences clear later.

The outspoken Belarusian leader struck a conciliatory note Tuesday during a meeting with the Russian chief of Moscow-dominated security grouping of ex-Soviet nations that includes Belarus. "Even though the Russian leadership has kept scratching us ... that hasn't enraged us against it," Lukashenko said, according to the ITAR-Tass news agency.