Prosecutors have vowed to get tough on protesters who spew hate ahead of an unprecedented £4.5million policing operation to deal with rival rallies on Sunday.

Keir Starmer warned on Saturday of a 'fight for the soul of this country' after the head of the Crown Prosecution Service announced a new hardline stance against those inciting hatred at protests.

Scotland Yard is gearing up for one of the busiest days for policing in years, with up to 80,000 protesters set to descend on the capital – which is also hosting the FA Cup Final.

Britain's biggest force is preparing to use armoured vehicles for the first time in a decade as it deploys 4,000 officers to tackle a series of protests on Sunday, including a Unite The Kingdom rally led by far-Right activist Tommy Robinson and a pro-Palestine demo to mark Nakba Day. Arabic for 'catastrophe', Nakba refers to the displacement of Palestinians in 1948 for the founding of Israel.

Visiting the Metropolitan Police's Command and Control Special Operations Room yesterday, the Prime Minister outlined a 'ramped-up justice system' ready to quickly haul violent offenders in front of judges, saying: 'We're in a fight for the soul of this country, and the Unite The Kingdom march is a stark reminder of exactly what we are up against.

'Its organisers are peddling hatred and division, plain and simple.

'We will block those coming into the UK who seek to incite hatred and violence. For anyone who sets out to wreak havoc on our streets, to intimidate or threaten anyone, you can expect to face the full force of the law.'

Eleven foreign far-Right agitators have been blocked from entering the country.

Earlier, Director of Public Prosecutions Stephen Parkinson announced new guidance urging prosecutors to consider whether protest placards, banners and chants viewed on social media may amount to offences of stirring up hatred.

He said: 'This is not about restricting free speech. It is about preventing hate crime and protecting the public, particularly at a time of heightened tensions.'

Offences of stirring up hatred under the Public Order Act carry a jail term of up to seven years.

For the first time under official protest restrictions, organisers and speakers at rallies will face prosecution if they are deemed to use the events as a platform for extremism or hate speech.

But Paula Dodds, who chairs the Metropolitan Police Federation, warned her rank and file officers were over-stretched by a steady stream of protests.

She said: 'There are not enough of us. Officers are emotionally and physically exhausted.'

It has emerged that Jewish worshippers will have to join part of the Nakba march route. Those leaving Westminster Synagogue must follow the route as the Met has refused to divert the rally.