Extremist views must not be allowed to “percolate through society”, a Cabinet minister has said as the Government prepared a fresh crackdown.

Ministers and officials are working on a new definition of extremism, with groups captured by the term set to be effectively blacklisted by the Government and public bodies, and cut off from public funding and engagement.

Communities Secretary Michael Gove is expected to set out the new definition in the coming week in the wake of the latest pro-Palestinian march, which saw tens of thousands of people protest in London about the suffering in Gaza.

Mr Gove warned some of the “good-hearted” people who have taken part in the series of protests since the Israel-Hamas war began could have inadvertently given credence to events organised or attended by extremists.

Health Secretary Victoria Atkins warned: “There are some people, sadly, who hold views that are contrary to the values that we hold as a country and we should not allow those views to percolate through society”.

She told Sky News there was a concern that in large-scale pro-Palestinian demonstrations “there can be a minority of people who hold and extol views that make the rest of us feel not just deeply uncomfortable, but if you are a Jewish resident of London, some have said that they feel worried about walking around London when these demonstrations happen, and that’s not right”.

The Health Secretary said the new approach would be a “balancing act” between “freedom of speech, but also the right of citizens to go about their daily lives”.

Mr Gove told the Sunday Telegraph the new definition of extremist groups would help protesters decide whether to attend pro-Palestinian events.

“If we’re clear about the nature of extremist organisations, then I think that means that some of the people – and there are good-hearted people who go on these marches, I don’t agree with them, but they’re moved by suffering and they want peace – but it may help some of them to question who are organising some of these events. I won’t go into details now, but we will later,” he said.

“Some of the events that have been organised have been organised by extremist organisations.

“That doesn’t mean that people who have gone on them are extremist, quite the opposite. But it means that you can begin to question: do you really want to be lending credence to this organisation? If you do, fair enough. But now there is no excuse for ignorance.”

Focusing on the chant of “from the river to the sea” – a reference to a Palestinian state stretching from the River Jordan to the Mediterranean – Mr Gove said “some of what’s said on these marches springs from an extremist ideology”.

“‘From the river to the sea’ is not a call for peace … when you’re saying ‘from the river to the sea’, you’re explicitly saying: ‘I want to see the end of Israel as a Jewish state, the Jewish homeland erased’.

The vast, vast majority of people in this country respect, tolerate difference – (they) welcome difference and diversity – it’s one of the things that make our country great

“Now, be clear about that and be clear about what that means.

“Be clear about the fact that you know a key Islamist demand is the erasure of what they see as the ‘Zionist entity’ or the ‘crusader Zionist state’.

“And, therefore, let’s be clear that there is a difference between a cry for peace and the legitimisation of an extremist position which intimidates and leads to hate.”

The Government’s new definition will replace one in the existing Prevent counter-radicalisation programme, giving “more specificity”, and will enable the Government and other public bodies to ban funding and engagement with Islamist and far-right groups.

Mr Gove sought to address fears from some Tories that the new definition could encompass gender-critical feminists or devout religious groups.

“It’s only extremism if you translate that into a political ideology that is anti-democratic,” he said.

“Private belief should be cherished. Free speech has to be protected.”

Mr Gove hinted that foreign governments such as Iran could be behind some of the extremist groups operating in the UK.

“One of the things that we’re explicitly looking at is the way in which foreign state and non-state actors seek to encourage extremism here,” he said.

“Again, this is inevitably sensitive work about which I can say only a very limited amount because it’s not only Iran that attempts to use some of these forces to destabilise British democracy.”

Meanwhile, the Observer reported that Mr Gove’s officials fear the new definition could face a legal challenge.

“The Government wants to launch this without a public consultation on the definition, or proper engagement with faith leaders,” said one official who has seen the proposals.

“It’s never going to work.”

For Labour, shadow chancellor Rachel Reeves said it was “right that we look again at the definition” of extremism.

“The most important thing from my perspective is that more is done to bring communities together,” she told Sky News’ Sunday Morning with Trevor Phillips.

“The vast, vast majority of people in this country respect, tolerate difference – (they) welcome difference and diversity – it’s one of the things that make our country great.

“But, of course, it is always right to tackle extremism and hatred wherever it rears its head.”

It’s been a sad period to witness this level of discord but, more seriously, to imagine that there are some communities in our country who don’t feel safe coming out and about and going into town. I was alarmed about this early on

Equalities and Human Rights Commission chairwoman Baroness Falkner told the Telegraph that the “discord” on the country’s streets since the Oct 7 Hamas attacks had shown that “we seem to be failing to integrate”.

She suggested immigrants should take courses in integrating into Western society.

“It’s been a sad period to witness this level of discord but, more seriously, to imagine that there are some communities in our country who don’t feel safe coming out and about and going into town. I was alarmed about this early on,” she said.

Highlighting a significant increase in immigration, she said: “We have to recognise that large numbers of first-generation migrants haven’t had the background of growing up in a rights-respecting country.

“What I would love to see would be a concerted programme of integration. Our citizenship test was a good innovation, but I think we need to reassess it, require people to take courses in integration.

“Germany does, for example, and I think we need to follow the model of other countries that, before people are granted citizenship, require them to take a course on what it means to live in Western democratic societies.”

Meanwhile, the frontrunner to be appointed as the Government’s adviser on tackling Islamophobia stepped away due to the abuse he had received.

Fiyaz Mughal, founder of Faith Matters and the Tell MAMA organisation, which tracks anti-Muslim hatred, told the PA news agency: “I have suffered over a decade with far right and Islamist abuse from extremist groups.”

He said that after it was reported that he was in line for the role, he received even more personal attacks and “I couldn’t take it any more”.

Mr Mughal said the Government “needs to do something” to protect him and others involved in speaking out about anti-Muslim attacks from being abused.

The Mail on Sunday reported that his appointment had been approved by Downing Street on Thursday, although sources said he was only on the shortlist.

The newspaper said his appointment was due to be announced on Monday.