A former high level Russian official who left President Vladimir Putin’s government was suddenly hospitalized after suffering a serious and rare neurological condition, CNN reported.

Anatoly Chubais is currently in a hospital in Europe suffering from Guillain-Barré syndrome, which his wife told Russian journalist and TV presenter Ksenia Sobchak he abruptly came down with.

According to Sobchak, Chubais’s wife said her husband is in critical condition.

“[His] state is unstable. He felt bad very suddenly, he began to stop feeling the arms and legs.”

Sobchak ran for president of Russia in 2018 and has been a critic of Putin, including his invasion of Ukraine.

She quoted Chubais saying: "I was hospitalized in one of the European clinics with a diagnosis of Guillain-Barr syndrome. Condition of moderate severity, stable."

Chubais resigned from his position as Kremlin special envoy on the environment in March.

Reuters reported at the time that he left Russia due to opposition to the Ukraine conflict.

Chubais, who was former Russian President Boris Yeltsin’s finance minister in the 1990s, was considered a political opponent of Putin’s during Putin’s early years in politics.

He had recently urged economic reforms and was considered one of the only liberals in the Russian government.