Sir Keir Starmer has blocked seven 'far-right agitators' from entering Britain after they were invited to Tommy Robinson's Unite the Kingdom rally on Saturday.
The Prime Minister used his 'make or break' speech yesterday to announce the bans as he sought to bolster his support among left-wing Labour MPs.
More than 100,000 people are expected to attend the Unite the Kingdom rally in central London, which Sir Keir said was 'designed to intimidate'.
Police have imposed strict conditions on the event and a separate march to mark Nakba Day, which commemorates the 'Catastrophe' of 1948 when thousands of Palestinians were displaced in the Arab-Israeli war.
The Home Secretary has the power to cancel a person's permission to enter or stay in the UK and Sir Keir said seven individuals had been targeted so far.
They include Ada Lluch, a Spanish anti-Muslim influencer who has defended the country's Franco dictatorship as preferable to democracy.
The 26-year-old accused the Government of trying to 'sabotage' Saturday's rally as she revealed her electronic travel authorisation (ETA) had been cancelled days after she agreed to attend.
Other speakers who have been blocked from entering the UK or the rally are Dutch far-right influencer Eva Vlaardingerbroek, an advocate of the 'great replacement theory' - which claims that white Europeans are being deliberately replaced with non-Western immigrants.
Those blocked from entering the UK include Ada Lluch, a Spanish anti-Muslim influencer who has defended the country's Franco dictatorship as preferable to democracy
Other speakers who have been blocked from entering the UK or the rally include Dutch far-right influencer Eva Vlaardingerbroek, an advocate of the 'great replacement theory'
Last month, anti-Islam influencer Valentina Gomez was excluded by Shabana Mahmood after a backlash from MPs and campaign groups.
The US-based personality – who gained notoriety through stunts including burning a copy of the Koran – threatened to defy the ban and travel by small boat while suggesting Donald Trump's White House would intervene if the authorities try to arrest her.
Ms Gomez was due to speak at the rally, having attended its previous protest in September.
Last week, right-wing US figure Joey Mannarino said he had also been blocked because his presence had been deemed not to be conducive to the public good.
The same justification was used for banning rapper Kanye West for his antisemitic comments.
Mr Mannarino, who has previously attended anti-migration events in Britain, including a rally by Britain First, has been criticised for his comments on migration and accused of misogyny.
In one tweet referring to a case against US President Donald Trump, he said he would 'never believe a victim of rape again in my life no matter the verdict in court'. He added: 'All rape cases have just become fake to me.'
Valentina Gomez - who filmed herself burning a Quran - had also been due to speak at the Unite the Kingdom rally
Joey Mannarino has had his Electronic Travel Authorisation (ETA) revoked by the Home Secretary on the basis his presence in Britain would 'not be conducive to the public good'
He has called migrants 'third-world parasites' and said that 'Europe is a rape-filled Islamic s***hole', adding: 'Who wants to see a bunch of Moslem inbreds?'.
He also previously reshared a tweet referring to 'liberal white women' holding up signs with the word 'love' and said: 'These women are begging to be raped'.
Mr Mannarino shared a screenshot of an email he received from the Home Office informing him his ETA had been revoked, and said: 'Today, I just woke up to this notice in my email.
'They have banned an American citizen from their country for no apparent reason whatsoever. I assume for matters of freedom of speech, but they haven't clarified.
'I will most certainly be appealing that decision and applying for a visa through the formal process to see exactly why they've deemed me ineligible to come over.
'Free speech is DEAD in the United Kingdom. Absolutely dead. The Labour government has taken whatever was left of it and destroyed it.'
In a speech on Monday, Sir Keir said the rally was 'designed to confront and intimidate this diverse country'.
He suggested more visiting speakers could be barred, adding: 'That is why this Labour Government will block far-right agitators from travelling to Britain.
'We will not allow people to come to the UK, threaten our communities and spread hate on our streets.'
The Prime Minister announced the bans during his 'make or break' speech in London yesterday
The names of the three other right-wing figures barred by the Government have not yet been disclosed.
Met Commissioner Sir Mark Rowley previously said he was 'concerned' about the scale of the Unite the Kingdom and Nakba Day marches, adding his force was 'looking hard at what conditions and powers we should use'.
The last Unite the Kingdom protest was attended by between 110,000 and 150,000 people.
The pro-Palestinian march, which will be joined by Stand Up to Racism group, will be separate from Robinson's rally and end up in Pall Mall.
Ms Mahmood has previously used her power to ban individuals whose presence is deemed 'not conducive to the public good' to ban Islamic hate preachers.
In January she cancelled the ETA of Shadee Elmasry, who had justified Hamas's October 7 terrorist attack on Israel and was due to take part in a speaking tour in Birmingham, Bolton and Ilford.