President Vladimir Putin’s longtime ally Dmitry Kozak has resigned as Kremlin deputy chief of staff, the RBC news outlet reported on Wednesday, citing sources familiar with the decision.

The departure follows a New York Times report last month that alleged Kozak had lost favor with Putin after objecting to the full-scale invasion of Ukraine.

Once seen as a powerful Kremlin fixer, he has since kept a low profile and reportedly ceded key responsibilities to Sergei Kiriyenko, the influential first deputy chief of staff.

Kozak submitted his resignation over the weekend and is weighing offers to work in the private sector, according to RBC. Interfax reported on Thursday that Putin had accepted the resignation, with Friday expected to be Kozak’s last day at the Kremlin.

As of early Thursday, the Kremlin website still listed him as deputy chief of staff. There was no immediate response from authorities in Moscow about the reports of Kozak’s resignation.

Born in Soviet Ukraine’s Kirovohrad region, Kozak worked in legal posts in St. Petersburg during the 1990s, when Putin served in the mayor’s office. He joined the federal government in 1999 and followed Putin into the Kremlin after his election the following year.