A Tommy Robinson-led demonstration gathered in Central London on Saturday afternoon as activists chanted: "We want our country back."
Thousands gathered on the Strand waving Union, English, Scottish and Welsh flags as they sung renditions of "Rule Britannia" and chanted "England till I die".
Robinson vowed the event would be "the biggest patriotic rally the UK has ever seen".
However, around 1,000 police officers have been deployed to the streets of the capital to “keep the peace” amid expected counter-demonstrations.
Protest groups Stand Up To Racism and former Labour leader Jeremy Corbyn’s Peace & Justice Project are set to march from Russell Square to Whitehall after branding Robinson a "fascist".
"Fascists are not welcome in London - or anywhere. Join the mass mobilisation to isolate fascist fraudsters like 'Tommy Robinson," the group wrote on social media.
The rally saw a mix of flags from the UK on show
PA
Those in attendance proudly sung 'Rule Britannia' and other patriotic songs
REUTERS
Tommy Robinson said the event was 'the biggest patriotic rally the UK has ever seen'
REUTERS
Robinson said his rally was to "unify" the UK, adding: "Today the people of Britain will send a message to the world.
"We will remain silent no longer. We want out country back."
The police have already used powers under the Public Order Act to try to keep the opposing groups apart amid fears of serious disruption.
Chief Superintendent Colin Wingrove, who is in charge of this weekend’s operation, warned that police will “intervene decisively” to deal with those who break the strict conditions about when and where they are allowed to demonstrate.
Tommy Robinson vowed today's rally would 'send a message to the world'
REUTERS
Thousands of men and women were in attendance
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He said: “Our first priority is to keep the peace to ensure that those exercising their right to lawful protest can do so safely.
“We have proactively used our powers under the Public Order Act to manage the timings and routes of marches and assemblies, ensuring that the groups are kept apart.
“Officers will intervene decisively to deal with any breaches of those conditions, prevent crime, and to respond to any other incidents.
“Everyone has a right to feel safe and be safe in London.
Counter-protesters called the Tommy Robinson event 'facist'
STAND UP TO RACISM
Over a thousand police officers were deployed to keep the marches separate
STAND UP TO RACISM
“Those who abuse the right to protest in an effort to unlawfully intimidate others or to use hate speech can expect to face police action.
“The police presence will be very visible and I would urge anyone out and about in London, whether participating in these events or not, to speak to an officer if they feel unsafe or wish to report an incident.”
