LONDON — The British government said on Tuesday that it had imposed sanctions on more than 370 individuals it described as oligarchs, political allies or propagandists for President Vladimir V. Putin of Russia, a major new crackdown that brings it closer in line with the European Union on an issue that has long dogged Britain.
The sanctions, announced by the foreign secretary, Liz Truss, include a travel ban and will freeze the assets of prominent Russians in business and government, including some of the wealthiest oligarchs and most senior officials in the Kremlin.
Among those on the latest list: Dmitri A. Medvedev, the former president of Russia; Prime Minister Mikhail Mishustin; Dmitri S. Peskov, the Kremlin press secretary; Maria Zakharova, a spokeswoman for Russia’s foreign ministry; Sergei Shoigu, the defense minister; and Mikhail Fridman, the billionaire founder of Alfa Bank, one of Russia’s largest private banks.
“We are going further and faster than ever in hitting those closest to Putin — from major oligarchs to his prime minister and the propagandists who peddle his lies and disinformation,” Ms. Truss said in a statement. “We are holding them to account for their complicity in Russia’s crimes in Ukraine.”
Last week, Britain imposed sanctions on Roman Abramovich, the billionaire owner of the Chelsea soccer club in London. But the government has faced criticism for moving slowly against other wealthy Russians, many of whom own property in London or have insinuated themselves into British politics and society.
The oligarchs targeted on Tuesday have an estimated combined net wealth of more than $130 billion. Some, like Mr. Fridman, own baronial residences in London. On Monday, eight protesters were arrested after occupying the balcony of a London mansion linked to another oligarch, Oleg Deripaska, who was targeted by sanctions last week along with Mr. Abramovich.
The latest batch of sanctions were imposed under a new Economic Crime Act, which Prime Minister Boris Johnson’s government introduced in an effort to try, belatedly, to stem the flow of corrupt money into Britain from oligarchs and other wealthy foreigners. The act enables Britain to automatically impose the penalties on people who are under European Union sanctions.
The government said it had developed its own sanctions cases against four major oligarchs: Mr. Fridman and two of his partners, Petr Aven and German Khan; as well as Oleg Matveychev, a member of Russia’s Parliament, whom British officials describe as a propagandist for Mr. Putin.