More than half of people have witnessed extremism “in some way”, while 83 per cent fear it is damaging society and democracy, new government figures show.

The findings of a survey of approximately 3,000 people by the Commission for Countering Extremism also show that the majority of people believe “a lot more” should be done to counter online extremism.

Of the public respondents who said they had witnessed extremism, Islamist extremism (59 per cent) was the most common, followed by far right (37 per cent) and far left (29 per cent) extremism.

Respondents who were classed as “practitioners” – meaning they have expertise in extremism – said they had witnessed more far right extremism (68 per cent) than Islamist extremism (64 per cent).

Home Secretary Sajid Javid will deliver a speech on the newly-published figures today, while Sara Khan, the government’s anti-extremism tsar, will say that “people are scared that violent extremists will incite or carry out an attack”.

In a speech to be delivered on Friday, she will add: “I was shocked to see that more than half of the respondents have witnessed extremism in some way, and that two-fifths of those that had witnessed it said they’d seen it in their local area.

“Communities are also deeply concerned about the impact of groups exploiting local tensions to spread hate and division.

“There are concerns from women, minorities-within-minorities and LGBTQ people that activists, through repeated intimidation and harassment, are shutting down their voices and preventing them from living freely.

“We must guard our right to debate, protest and offend. We should use the word ‘extremism’ with caution. I believe we can, and must, do more.

“There is a real worry about intolerance, abuse and polarisation in public life and debate and the space this gives extremism.

“I believe we need to put forward a positive vision of countering extremism, which is about upholding those democratic values that make this country great.” 

Three quarters of the public respondents found the Government’s current definition of extremism “very unhelpful” or “unhelpful”, while just over half of practitioners found it either “very helpful” or “helpful”.