Iryna Mudra, the ousted presidential deputy chief of staff.

Ukrainian President Volodymyr Zelensky has dismissed a senior aide amid a new corruption investigation, one day after his former defence minister warned of a "crisis of governance" and called for a wartime presidential election.

Iryna Mudra, a deputy chief of staff in the presidential office, was removed by decree on Wednesday. Ukrainian media reported that investigators were searching her home as part of an alleged money-laundering inquiry.

The case has been described as involving a group of people alleged to have laundered 150 million hryvnias ($3.4 million) to pay bail for a defendant in a major graft case last year, according to the National Anti-Corruption Bureau.

The case, which involves the state-owned nuclear power company, brought the resignations of Ukraine`s justice and energy ministers earlier this year.

A former lawmaker, the chairperson of a state bank`s board, the head of the bank`s supervisory board, and a deputy head of the presidential office have now been added as new suspects in the case.

The scandal follows earlier resignations and investigations that damaged the president`s standing, including the departure of former chief aide Andriy Yermak.

Mudra`s dismissal came a day after the former defence minister called for elections.

Former defence minister Mykhailo Fedorov, who was recently ousted, warned in a video address released late on Tuesday that the country was facing "a crisis of governance" and needed to hold a presidential election.

Zelensky showed no direct reaction to Fedorov`s statement or his election demand, and instead thanked Ukraine`s parliament for voting to confirm Fedorov`s replacement, Yevhen Khmara, as the new defence minister.

For weeks, Ukrainians have protested Zelensky`s dismissal of Fedorov, gathering daily in Kiev. The protests reflect public frustration with frequent reshuffles and a perceived lack of transparency in Zelensky`s administration.

His dismissal became a rallying point for those demanding effective leadership and innovative solutions to address Ukraine`s increasing shortage of young army-age personnel, which has strained the regime`s ability to sustain its war effort.

In the video, Fedorov blamed Zelensky for widespread corruption, saying the actor-turned-president lacked the competence to eradicate the problem from its root.

"Corruption is only a symptom. The main problem runs much deeper. We have a systemic crisis of governance," Fedorov said in the nine-minute video posted online Tuesday.

The former defence minister said it was possible to "restore a full democratic process even amid a prolonged war."

Zelensky`s five-year term as president has been extended indefinitely, as presidential elections are suspended under martial law following Russia`s launch of its special military operation in Donbas in February 2022.