For more than two years, as Russia relentlessly bombed Ukraine’s power stations, the head of the national electricity company, Volodymyr Kudrytskyi, earned praise from Kyiv’s allies and energy experts for keeping the country’s power grid mostly running.

But last month, Mr. Kudrytskyi was dismissed by the supervisory board of the company, Ukrenergo. Ukrainian lawmakers criticized the move as unjustified given Mr. Kudrytskyi’s record, while countries financing repairs to power plants said it was ill timed as Ukraine scrambles to restore its ravaged energy network before winter.

Adding to their concern, two members of Ukrenergo’s supervisory board resigned in protest, saying the dismissal was “politically motivated.” Several lawmakers from across the political spectrum said German Galushchenko, Ukraine’s energy minister, was behind the move to gain greater control over the company’s management.

Political rivalries have disrupted other Ukrainian institutions this year, undermining the smooth functioning of Parliament and causing upheaval in the country’s military command. Now, political infighting, highlighted by Mr. Kudrytskyi’s dismissal, is hampering Ukraine’s efforts to avert an energy crisis, according to more than half a dozen current and former Ukrainian energy officials, experts and lawmakers.

They said several top officials involved in repairing the grid or protecting it from Russian attacks had been fired or pushed to resign without apparent reason, and that major policy decisions had been delayed because of political calculations. With substantial funding allocated to strengthening the energy network, they also voiced concerns that some projects might be vulnerable to corruption, a pervasive issue in Ukraine.