FILE PHOTO: Ukraine's President Volodymyr Zelenskiy and Head of the Presidential Office Andriy Yermak walk, amid Russia's attack on Ukraine, in Kyiv, Ukraine January 22, 2024. REUTERS/Gleb Garanich/File Photo

By Dan Peleschuk

KYIV (Reuters) -Ask Ukrainians who the country's most powerful figure is after the president and many will say Andriy Yermak, his chief of staff and a key negotiator during four years of war when Western financial and military aid has kept Kyiv in the fight.

Yermak, a friend of President Volodymyr Zelenskiy and his trusted right-hand man, is ensnared in an evolving corruption scandal after anti-graft agents searched his property on Friday.

Yermak, 54, has said little about the searches, which came at a perilous time for Kyiv as it faces U.S. pressure to make big concessions to Moscow to end its war on his country and lacks the soldiers or weapons to push Russian forces back.

"A lot has happened at the same time," Mykola Bielieskov, a senior analyst at Ukrainian charitable foundation Come Back Alive, said before Yermak's property was searched.

"Scandals within the country, problems at the front, uncertainty in Europe, pressure from the Russian Federation and the United States."

YERMAK'S LONG FRIENDSHIP WITH ZELENSKIY

Yermak, who was born in Kyiv and started out as a lawyer before setting up a media company, has been at Zelenskiy's side since long before Russia's full-scale invasion in 2022.

They met in the early 2010s, when Zelenskiy was a rising star in television and Yermak was an emerging figure in Ukrainian media.

When Zelenskiy ran for the presidency in 2019, Yermak was on his team and later cemented his place at the top of Zelenskiy's administration.

Whether wearing a sharp suit in the halls of power while visiting European countries or khaki fatigues on visits to frontline positions, Yermak has been a constant presence beside Zelenskiy - a burly figure towering over his diminutive boss.

Yermak has survived several government reshuffles and exudes confidence, despite widespread public mistrust of an unelected official yielding so much power.

He has been a primary point of contact with two U.S. administrations, helps coordinate prisoner exchanges and peace talks, and is involved in lobbying Kyiv's partners for weapons, funding and sanctions against Moscow.

HAS THE SCANDAL CAUGHT UP WITH HIM?

Little was known on Friday about what anti-corruption agents were searching for at Yermak's apartment. He said he was cooperating fully.

The watchdogs that ordered the searches did not say what they were connected with.

Ukraine has been mired in scandal over an alleged plot to control contracts at the state atomic agency totalling $100 million in kickbacks and laundered money as Ukraine tries to protect energy infrastructure from Russian airstrikes.

Ukrainians are shocked by the scale of the case and outraged that it centres around energy facilities when power, water and heating outages are frequent because of the Russian attacks.

Opposition lawmakers and some members of Zelenskiy's party have called for Yermak's dismissal, although he has not been named a suspect in the case.

In an interview with The Atlantic published on Thursday, Yermak said the fact that Zelenskiy had appointed him to lead Ukraine's negotiating team in peace talks with U.S. and European partners underlined the president's trust in him.

"The pressure is enormous," Yermak said. "He trusted me with these negotiations that will decide the fate of our country. And if people support the president, that should answer all their questions."

UNCERTAINTY COMES AT A PRECARIOUS TIME

Zelenskiy remains broadly popular, but sacrificing a close ally could help shore up support at home and abroad at a moment the president himself has described as Ukraine's most difficult.

If Yermak is forced out, it could be seen as a commitment to "clean the house" - but also as a sign that corruption allegations are getting closer to the president himself.

The chief suspect in this month's probe is a former business associate of Zelenskiy's.

Concern among U.S. officials over allegations of graft, which have so far cost two ministers their jobs, has undermined Zelenskiy at a time when he most needs their trust.

Ukraine is under U.S. pressure to accept peace proposals that Russia says must involve Kyiv giving up territory and agreeing to limit the size of its armed forces in future.

Russian President Vladimir Putin has also sought to undermine Zelenskiy by saying he is not a legitimate leader because he has exceeded his five-year term although Ukrainian martial law forbids wartime elections.

The corruption scandal has also emerged as Ukraine tries to show the European Union it is fighting corruption, a key task for it to join the wealthy bloc.

(Additional reporting by Yuliia Dysa and Mike Collett-White; Writing by Mike Collett-White; Editing by Timothy Heritage)