N Anjem Choudary in his neighborhood, Ilford, in northeast London, on October 1, 2014. (Andrew Testa/For The Washington Post)

Anjem Choudary, one of Britain’s best-known radical Islamist preachers, was charged Wednesday with encouraging people to support the Islamic State through lectures published online, authorities said.

The trial of Choudary and an associate, Mohammed Mizanur Rahman, will be a major test of the British government’s new strategy against extremism in all its forms.

Britain is among the Western countries seeking to undercut ­Islamic State recruitment and other outreach. Several Britons have risen to prominence in the Islamic State, including Mohammed Emwazi, also known as “Jihadi John,” who has appeared in videos showing the beheadings of foreign hostages.

Choudary, 48, and Rahman, 32, face charges of fanning support for the Islamic State — also known as ISIS and other names — between June 29, 2014, and March 6, according to a statement by London’s Metropolitan Police.

Fans of Anjem Choudary have their photo taken with him in a shop in Ilford, a neighborhood in northeast London, on October 1, 2014. (Andrew Testa/FTWP)

Choudary and Rahman appeared before the Westminster Magistrates’ Court in London on Wednesday, where they indicated they would plead not guilty.

Sue Hemming, head of Special Crime and Counter Terrorism at the Crown Prosecution Service, said in a statement that the pair is accused of drumming up “support for ISIS in individual lectures which were subsequently published online.”

Choudary, a lawyer by training, has more than 32,000 followers on Twitter. He has led various radical groups that were later banned for extremist activities, including al-Muhajiroun, a group that once called the Sept. 11 hijackers “the Magnificent 19.” He has never been convicted of anything beyond organizing an unlawful demonstration.

Rahman, his associate, served two years in prison for his part in a 2006 protest over a Danish newspaper’s publication of cartoons satirizing the prophet Muhammad.

In a major speech last month, British Prime Minister David Cameron laid out the government’s strategy for tackling Islamic extremism, calling for a tough stance on what he called “peddlers of hatred.”

Although Cameron provided few specifics, many viewed the speech as a signal that the government would be taking a less tolerant approach on extremism.

“I saw it as equivalent to Tony Blair’s speech after 7/7 [the 2005 London transit bombings], when he made a speech saying the rules of the game are changing, which was meant to signal that the boundaries of tolerance were going to change,” said Clive Walker, an expert in terrorism legislation at the University of Leeds.

“But we have yet to see
what Cameron’s pronouncements mean in practical terms,” he said, noting that the British government is expected to publish a new counter-extremism bill later this year.

Choudary was arrested last September — before Cameron’s speech — but analysts said that when the British prime minister said he wanted to introduce new powers to deal with “facilitators and cult leaders,” he was referring to people like Choudary and his associates.

“When Cameron was talking about nonviolent extremists, these were the people he was thinking about,” said Peter Neumann, a terrorism expert at King’s College London. “The inability to prosecute them has created a lot of frustration in the past.”

Choudary and Rahman were among nine men arrested last year as part of a Scotland Yard investigation into alleged encouragement of terrorism.

Choudary is a controversial figure, with many saying that he’s little more than a clown figure with few followers. Others note that he has links to several people who have been convicted of terror offenses.

Neumann said that in recent years, Choudary’s influence has spread throughout Europe. “So in almost every European country you can find identical groups
of al-Muhajiroun, his original group, including Sharia4Belgium, Sharia4Holland, Sharia4France, Profetens Ummah in Norway, Kaldet til Islam in Denmark, Millatu Ibrahim in Germany — all of these groups were inspired or directly set up by Anjem Choudary, and they have proved a significant provider of people to the Islamic State,” he said.

Choudary has denied reports that he is responsible for sending people to fight for Islamist militant groups. “I don’t think there’s one example of anyone in Iraq, Afghanistan or Syria, or any place in the world, whether passed away or whether alive today, who has actually said that I’m here because Mr. Choudary asked me to go abroad or I was incited or encouraged by him to go abroad,” he told the BBC.

Choudary has become increasingly enthusiastic in his support for the Islamic State since his arrest last year. He told the Mirror, a British newspaper, that he would move his family to the region if he could travel — British authorities seized his passport when he was arrested. “I’d go tomorrow. I’d love to bring my children up there,” he told the newspaper.

Read more:

In Britain, Islamist extremist Anjem Choudary proves elusive

How Mohammed Emwazi became Jihadi John: 5 key takeaways

Britain’s Cameron outlines strategy to fight Islamist extremism

Today's coverage from Post correspondents around the world