British Prime Minister Rishi Sunak has warned that democracy is being targeted by extremists.
Mr Sunak said there are "forces here at home trying to tear us apart".
Speaking at a lectern outside Downing Street, Mr Sunak warned about the current situation in Britain, in the aftermath of the 7 October attacks by Hamas against Israel.
"In recent weeks and months, we have seen a shocking increase in extremist disruption and criminality," he said in a hastily arranged address to the nation.
And he said the victory of George Galloway in the Rochdale by-election was "beyond alarming".
He said: "In recent weeks and months, we have seen a shocking increase in extremist disruption and criminality.
"What started as protests on our streets have descended into intimidation, threats and planned acts of violence.
"Jewish children fearful to wear their school uniform lest it reveals their identity. Muslim women abused in the street for the actions of a terrorist group they have no connection with.
"Now our democracy itself is a target. Council meetings and local events have been stormed. MPs do not feel safe in their homes. Long-standing parliamentary conventions have been upended because of safety concerns.
"And it's beyond alarming that last night, the Rochdale by-election returned a candidate that dismisses the horror of what happened on October 7, who glorifies Hezbollah and is endorsed by Nick Griffin, the racist former leader of the BNP."
Mr Galloway said he did not understand Mr Sunak's suggestions that he "glorifies Hezbollah".
"I'm not responsible for whoever declares they endorse me...I've never met Mr Griffin and have no intention to," Mr Galloway told Channel 5 News.
"I don't know what the glorifying of Hezbollah is all about but maybe he can tell me on Wednesday at Prime Minister's Questions if he's got the guts."
Mr Galloway added that he "abhors extremism just as much as (Mr Sunak)" and "also agreed with him when he said change can only come through the democratic process".
During his address, Mr Sunak said: "We are a country where we love our neighbours and we are building Britain together. But I fear that our great achievement in building the world's most successful multi-ethnic, multi-faith democracy is being deliberately undermined.
"There are forces here at home trying to tear us apart. Since October 7th, there have been those trying to take advantage of the very human angst that we all feel about the terrible suffering that war brings to the innocent, to women and children, to advance a divisive, hateful ideological agenda.
"On too many occasions recently, our streets have been hijacked by small groups who are hostile to our values and have no respect for our democratic traditions.
"Membership of our society is contingent on some simple things that you will abide by the rule of law. And that change can only come through the peaceful democratic process. Threats of violence and intimidation are alien to our way of doing things. They must be resisted at all times.
"Nearly everyone in Britain supports these basic values. But there are small and vocal hostile groups who do not. Islamist extremists, and the far right feed off and embolden each other. They are equally desperate to pretend that their violence is somehow justified, when actually these groups are two sides of the same extremist coin."
Mr Sunak said Islamist extremists and far-right groups are "spreading a poison" and "want us to believe that our country and the West more generally is solely responsible for the world's ills".
He said: "When these groups claim that Britain is and has been on the wrong side of history, we should reject it and reject it again. No country is perfect.
"But I am enormously proud of the good that our country has done. Our place in history is defined by the sacrifices our people have made in the service of their own freedom and that of others.
"And when these groups tell our children that they cannot and will not succeed because of who they are, when they tell children that the system is rigged against them, or that Britain is a racist country, this is not only a lie, but a cynical attempt to crush young dreams and turn impressionistic minds against their own society.
"I stand here as our country's first non-white Prime Minister, leading the most diverse Government in our country's history to tell people of all races, all faiths and all backgrounds, it is not the colour of your skin, the God you believe in, or where you were born that will determine your success, but just your own hard work and endeavour."
He added that he respects that the police have a tough job in policing the protests "but we must draw a line".
Labour leader Keir Starmer appeared to back the Prime Minister's message calling for unity in the country.
In a statement after Mr Sunak's address, he said: "The Prime Minister is right to advocate unity and to condemn the unacceptable and intimidatory behaviour that we have seen recently.
"It is an important task of leadership to defend our values and the common bonds that hold us together.
"Citizens have a right to go about their business without intimidation and elected representatives should be able to do their jobs and cast their votes without fear or favour.
"This is something agreed across the parties and which we should all defend."
Earlier, Mr Sunak spent the day in Scotland, giving a speech to the Scottish Conservative conference in the afternoon.
Shortly after the Conservative party leader had finished taking questions from party members in Aberdeen, Downing St confirmed he would be travelling immediately to London where he intends to make public remarks.
"The Prime Minister's address will touch on recent events, including in Parliament last week, and the need to protect our democratic processes," Downing Street said in a statement.
While in Scotland, Mr Sunak urged voters to stick with the Tories at the next general election.
He argued that his party was "starting to deliver" and used his standard attack line that putting Labour into power would "take the UK back to square one".
A contest to elect a new UK government is widely expected to take place this year, with an election legally having to be held by January 2025.
The Tories are well behind Labour in opinion polls, with some putting Mr Starmer's party as much as 20 points in front.
