The moves would be combined with a “positive campaign to promote British values” and extra money for English language lessons.
The Muslim commentator Mohammed Ansar attacked the “blacklist” proposal. He claimed that “anti-Muslim McCarthyism” had reached a new low ahead of the general election.
Peter Tatchell, the human rights campaigner, tweeted: “UK govt to ban hate preachers. How do you define hate? Danger of McCarthyism. Threat to free speech.” The Islamic Human Rights Commission accused Mrs May of playing the Islamophobia card and of attempting to “curtail the fundamental rights of Muslims under the pretext of combating extremism”.