LONDON (Reuters) - To his detractors, including the British government, Salman Butt is an extremist whose views on Islam fly in the face of Britain's values and help foster an atmosphere where young Muslims can be radicalised by militants.
Even though he is not accused of supporting militant groups or violence, the British authorities believe it is only by cracking down on activists like Butt and denying a forum for their ideas to be widely heard that the threat posed by jihadis and groups such as Islamic State can be countered.
But critics, ranging from civil rights groups to leading academics and lawmakers, say what the government is trying to do amounts to a curb on free speech which could drive a wedge between the authorities and Britain's 2.8 million Muslims
They argue if anything such plans will only make the problem worse and amount to an attack on the fundamental liberties the government wants to protect.
"Over the last few years the circle of who and what is considered extreme has been expanding slowly," said Butt, 30, who is taking the British government to court over its counter-extremism strategy.
"Before it was just somebody committing crimes or calling for violence and then they expanded more and more to everyday people who happen to maybe criticize certain aspects of the government policy or hold certain conservative Islamic views," he told Reuters.
The problem facing Britain and other Western governments is the same one with which they have wrestled since the Sept. 11, 2001 attacks on the United States: how to stop their young citizens being radicalised without been seen to censor critics.
Thousands of Muslims, including more than 800 Britons, have left Europe for Iraq and Syria, many to join Islamic State (IS), while the recent deadly attacks seen in Paris, Brussels and Nice are a graphic illustration of the risk posed by some lured to a violent Islamist cause at home.
The revelation on Tuesday that Anjem Choudary, Britain's most high-profile Islamist preacher, has been convicted for inviting his followers to support Islamic State has again brought the issue to the fore.
Choudary was convicted last month although this could not be reported until Tuesday to avoid prejudicing the jury in a separate case. It ended a streak of many years during which he served as the leader of banned organizations but dodged prosecution by carefully managing his public remarks.
Critics questioned why it had taken so long to act against someone who had been a leading radical Islamist figure for two decades and whose followers had been involved in militant plots and acts of violence across the world.
"There should be zero tolerance toward any cleric - Muslim or otherwise - who advocates extremist views and rejects British values," Britain's top-selling Sun newspaper said. "Britain has been tolerant of men like Choudary for too long."
For those such as new British Prime Minister Theresa May, tackling extremism means no longer tolerating those who reject the country's values: democracy, free speech, equality and the rule of law.
"Where non-violent extremism goes unchallenged, the values that bind our society together fragment," May, who had been interior minister for six years before taking over the Downing Street reins, said in a speech in February.
"So while by no means all extremism leads to violence, it creates an environment in which those who seek to divide us can flourish."
May, in her former guise as interior minister, was responsible for drawing up a proposed Counter-Extremism bill with bans for individuals or groups deemed extremist and closures of places where radicals thrive, including mosques.
However, there is still no sign of the legislation, with the Home Office (interior ministry) saying it would come in "due course". One main obstacle is who decides who or what is extremist.
"Providing a clear definition of extremism is a difficult task and the government has yet to succeed in doing it," said senior opposition Labour lawmaker Harriet Harman, head of the UK parliament's Joint Committee on Human Rights which produced a critical report on the government plans in July.
Even Finance Minister Philip Hammond admitted in May the issue was "a minefield": "The line between acceptable and non-acceptable behavior is fine and fraught with dangers," he said.
Last September, Butt, 30, who runs a discussion website Islam21c, was one of the first to fall foul of the moves to clampdown on non-violent extremists after being identified by a secretive cross-government Extremism Analysis Unit, established to pick out groups or individuals of concern.
The activist, who has a biochemistry doctorate, was named in a Downing Street press release on "hate speakers" as one of six figures who gave talks at university campuses and were "on record as expressing views contrary to British values".
A later explanation given by the government to parliament said he had appeared to compare homosexuality to paedophilia and had spoken alongside figures from CAGE, a campaign group that gained attention for contacts with Mohammed Emwazi, the now-dead British militant known as "Jihadi John" who appeared in Islamic State videos beheading foreign captives.
Butt said the accusations against him were "complete rubbish", and is now taking legal action to challenge the government's way of identifying extremists and its "Prevent" strategy, its much-criticized policy to stop radicalisation.
"What has happened over the last 10 years of counter-terrorism policy is it's completely going about it in a very destructive way," he said.
"The government need to do a job to keep people safe but the way it's being done, especially recently, not only are they looking in the wrong place ... but they are completely ignoring the negative effects it's having on community relations."
It is not just those like Butt who are targeted that are concerned. In January, Professor Louise Richardson, the Vice-Chancellor of Oxford University, said it was better to let extremists speak on campuses and challenge their views than to simply ban them.
David Anderson, Britain's terrorism law watchdog, has warned that plans to clamp down on individuals and organizations accused of extremism could backfire by playing into the hands of militant recruiters.
But those who back the government's intent say allowing extremists free rein in public forums or at universities exposes vulnerable people to their messages. They point out that graduates or students at British universities have been involved in numerous militant plots including Emwazi and Nigerian "underwear bomber" Umar Farouk Abdulmutallab.
Rupert Sutton, director of Student Rights, an organization that campaigns against extremism on university campuses, said people with controversial views were often given a platform where their opinions were not questioned.
"They're too often given a free pass," he told Reuters. "If you put it as a dichotomy between either freedom of expression or ban them from speaking that is too binary. What we need to think about is how we are going to make it so that when they do come to speak they face challenge rather than being banned."
He said the focus should be on using existing legislation to tackle people like Choudary, even if he had long proved adept at ensuring he did not break the law.
"When someone is as effective at it as Choudary is, you are going to get people saying: 'How is he allowed to go around on the street doing this?'" he said.
editing by Peter Graff