KIEV, Ukraine (AP) — Thousands have rallied in the Ukrainian capital to support President Petro Poroshenko who is trailing in opinion polls ahead of this Sunday's election.

Poroshenko will be hoping he can help turn the tide in a televised debate Friday against his opponent, comedian Volodymyr Zelenskiy, who grew popular thanks to a television show where he plays the Ukrainian president.

Poroshenko warned supporters in Kiev that a victory for Zelenskiy would damage the country's closer economic and political cooperation with the European Union.

He said Zelenskiy would be a weak president to the benefit of Russia, which annexed Ukraine's Crimean peninsula in 2014 and has been bankrolling separatists in Ukraine's east.