Welcome to the NewsHour. We begin tonight with a political earthquake in Ukraine.

President Volodymyr Zelensky's chief of staff, Andre Yermak, the country's second most powerful person,

has been forced to resign amid a corruption scandal. This comes as Ukraine has enmeshed in negotiations

with the Trump administration on a possible end to Russia's war in Ukraine. Special correspondent

Jack Hewson is in Kiev. Jack, who is this chief of staff? And why is this such a big deal?

Well, John, Andrew Yermak, as you mentioned, was President Zelensky's chief of staff and essentially

the second most powerful man in the country. Zelensky came to power on the back of a landslide election in 2019,

and with that authority, centralized power around the president's office,

and Yermak was a very big part of that.

Officially Ukraine is a hybrid premier presidential system,

but under Zelensky and Yermak is taken on a much more of a top-down executive

dominated shape. And under wartime powers, which include martial law and the freezing of any

presidential or parliamentary elections, that's centralised even more. As one anti-corruption

activists put it to me earlier this evening, Zelensky is the face of government

while Yermak was the brain. So for Yermak to be gone, it's huge. Corruption, there is an embezzlement

scandal that's enmeshing many high-ranking officials in Zelensky's circle. Tell us about that.

Well, the scandal is about an investigation by the anti-corruption authorities called Operation Midas,

which has resulted in a string of high-level raids and charges over the last month.

There have been a laundry list of high-ranking cabinet officials, including a former deputy

prime minister, have either been charged or named.

But the cornerstone figure in all of this is a man named Timor Mindich.

He's the former business partner of Zelensky, with whom he set up a media company before he was president.

...