Dozens of anti-migrant protesters waded into the sea in Portsmouth to confront 140 asylum seekers rescued from a packed mega-dinghy which had been allowed to leave France.
The group sprinted across Eastney Beach and entered the water on Sunday afternoon, chanting 'stop the boats' and 'enough is enough' at the moment migrants arrived on a UK Coastguard vessel.
Clips posted online later showed asylum seekers being ushered off lifeboats to shore, where they were met by several buses which took them to a processing centre in Kent.
The incident was the flashpoint that then triggered around 500 demonstrators blocking the road to stop coachloads of new arrivals leaving overnight.
After being dispersed by riot police at 3am on Monday morning, some got into cars and followed the buses on their journey to Kent today.
It is the second major UK anti-migrant protest in two days after the Port of Dover was shut down on Saturday.
More than 500 protesters gathered on the Hampshire coastline and dozens entered the sea four miles from Britain's Royal Navy headquarters to demand the asylum seekers be returned to France.
The mega-dinghy had set off from the Baie de Seine in Normandy – a 180-mile drive from Calais – suggesting people smugglers are expanding their launch points along the French coast to evade enforcement efforts.
But rather than intervene, the French coastguard shadowed the vessel for ten hours, claiming it was too dangerous because of the number of people on board.
British lifeboats, supported by a helicopter and a plane, then took over and brought the migrants to the UK.
Following calls to action on social media, protesters flocked to the coast and spent at least five hours on the beach and in the water.
They then attempted to stop the migrants being taken to Kent in a demonstration that went on until 3am on Monday, when police threatened arrests after a dispersal order was imposed.
A protester standing in the water as around 140 migrants who were brought into Portsmouth
The protest is thought to have been spearheaded by Daniel Thomas, pictured as the migrants landed, a Tommy Robinson associate from Portsmouth
Demonstrators were heard shouting 'stop the boats' and 'enough is enough' as they blocked roads until around 3am as they tried to stop migrants being taken by bus to Kent
After being dispersed by riot police, some got into cars and followed vans carrying the asylum seekers on their journey from Portsmouth to Dover
Shadow Home Secretary Chris Philp said: 'The last 24 hours have seen multiple violations of the UK border by mega-dinghies full of illegal immigrants which the French authorities have allowed to depart.
'Andy Burnham and Shabana Mahmood have been boasting about French action, but hundreds of illegal immigrants arriving in just a few hours shows this is not working
'Their weak approach is leaving our border wide open, with almost 20,000 illegal immigrants crossing so far this year. Only rough seas have prevented even more crossings.'
Hampshire and the Isle of Wight's Tory police and crime commissioner Donna Jones said it is a 'significant issue' for the Government if people smugglers shift their destinations away from Dover.
In protest footage shared on social media, a riot officer appeared to be pushed from his motorbike as demonstrators, many wearing caps and hoods, shouted: 'Shame on you.'
Further clips showed officers carrying shields ordering the crowd to 'get back' before pushing some protesters away from a nearby police van.
The protest is thought to have been spearheaded by Daniel Thomas, the Tommy Robinson associate from Hampshire whose Patriot Platform group organised a mass demonstration in Dover on Saturday.
Livestreaming the protest Thomas – also known as Danny Tommo – said yesterday: 'It was only [on Saturday in Dover] when we warned them that we will not accept this any more, and that it is no longer an option to tell us the boat numbers are down.
'This isn't about the numbers being down. This is about understanding that this has to come to an end now.'
Protesters gathered on the beach - and some waded in to the water try to disrupt the arrival - at the moment migrants arrived on a UK Coastguard vessel having crossed to Portsmouth
A pile of lifejackets by the road at Eastney, where the migrants landed
Hundreds of protestors clashed with police near Eastney beach in Portsmouth last night after a dinghy carrying 140 asylum seekers was escorted to the shore
Riot police were deployed to the scene, though none of the protesters are thought to have been arrested
Crowds stayed in the area until as late as midnight on Sunday
Unlike in Dover, the hundreds of protesters this time chose not to wear masks or balaclavas, although many were dressed in black.
The Baie de Seine to Portsmouth crossing is thought to have been one of the longest ever people-smuggling trips.
HM Coastguard sent two lifeboats, a coastguard helicopter, a fixed-wing aircraft and rescue teams to ensure the asylum seekers reached the British shore safely.
In some clips riot officers appear to be sprayed with water from super-soakers as dozens watching on record them on their phones.
Thomas, who livestreamed the event on YouTube, was heard urging his supporters to 'get in your cars and get down here' as he stood waist-deep in the sea.
Separate footage meanwhile appeared to show a woman delivering supplies to protesters via canoe.
The authorities in France have said that it is unusual for a migrant boat to depart from the Baie de Seine, nearly 200 miles from the usual launches.
A Maritime and Coastguard Agency spokesman said: 'In response to a report on September 6 of a small boat heading towards the Hampshire coast, HM Coastguard sent lifeboats, an HM Coastguard helicopter, an HM Coastguard aeroplane and HM Coastguard Rescue Teams.
'Border Force, Border Security Command, Hampshire Police and South Central Ambulance Service were also sent.'
Councillor George Madgwick, leader of Reform UK in Hampshire, wrote in a post on X that 'over 100 migrant men' had arrived in Portsmouth.
Reform UK leader Nigel Farage meanwhile posted: 'A boat launched from Baie de Seine, 170 miles from Calais, arrived on the beaches of Hampshire for the very first time. This is a joke. Only Reform will send the boats back.'
Migrants scramble on board a dinghy in an attempt to cross the English Channel to Britain (A boat in Gravelines, Calais, is pictured, in a separate incident yesterday)
Commissioner Donna Jones said officers from other forces were brought in to help amid fears this 'is just the start' of protests.
She said: 'Last night we had mutual aid, public order police officers sent from police forces across the country including the Metropolitan Police Service.
'We also had a number of our own police officers, obviously, from Hampshire and the Isle of Wight Constabulary trying to take back control of the roads, forming a line and holding a few hundred protesters back.
'This is just the start, if this continues, these numbers will grow from the protesters. They were making their point that they don't want Portsmouth to become a destination'.
She said it will be a 'significant issue' for the Government if people traffickers shift their destinations across England's south coast.
The crossing to Portsmouth came in the same week Prime Minister Andy Burnham and French President Emmanuel Macron met to discuss how to 'scale up' efforts to reduce small boat crossings.
Only last month, a small boat carrying record numbers of migrants – believed to be more than 230 – successfully crossed the English Channel.
And earlier this week hundreds of anti-migrant protesters donning balaclavas brought the Port of Dover to a standstill. Demonstrators were chanting 'stop the boats' while blocking many of the town's roads.
Some of those in attendance claimed links to Thomas's anti-migrant Patriot Platform.
Kent Police were thought to have been 'unaware' that the protest was taking place, leaving them 'thin on the ground' as hundreds marched the streets of the town.
Mike Tapp, the Labour MP for Dover and Deal and former Home Office minister, said: 'I will be looking urgently on Monday to ask questions around why we didn't know about this, because we do tend to know when protests are coming to the area, and they tend to be peaceful, and laws aren't broken, and obviously the police have the resources to manage that.
'But in this instance, it would appear that the police didn't know about it, and the resources were pretty thin on the ground, to be quite honest from what I saw. We know that laws were broken because they were blocking the roads and wearing face coverings.'
In response, Kent Police told the Daily Mail it was a 'spontaneous event and was policed accordingly'.
Police made no arrests and escorted the protesters to Dover Priory train station at around midday.
At least 100 people were seen boarding a train to Ramsgate, with some since spotted in nearby Sandwich where 'police are in attendance'.
Hard-Right Patriot Platform was founded earlier this year by Daniel Thomas, a convicted kidnapper and associate of Tommy Robinson.
The protesters blocked roads leading to the port, sparking warnings of delays for holidaymakers
Sharing clips of the protest in Dover to his social media, Thomas wrote: 'It's time. Protect Our Country! And more importantly, our women and children! This is our warning.'
Government minister Emma Reynolds today called the 500 protesters 'thuggish and intimidating'.
The Treasury Chief Secretary said: 'I absolutely support people's right to peaceful protest. But this crosses a line and I just want to take the opportunity to thank the police and other emergency services who have brought this under control.'
A Government spokesman said: 'We condemn the intimidating and thuggish behaviour we are seeing tonight.
'The right to peaceful protest is fundamental to our democracy, but it must never cross a line into disorder.
'We thank the emergency services who are working to safely manage this situation.'
Hampshire Constabulary said: 'This evening, we have been working alongside and assisting our partners from Border Force, Maritime & Coastguard Agency and Portsmouth City Council at Eastney Marina following the arrival of a boat crossing the channel.
'We have officers in the area to ensure the prevention of any disorder. We ask that people please avoid the area. A dispersal order is in place until tomorrow evening. Anyone who refuses to comply with the direction to leave the area is liable for arrest.
'We can also confirm that Border Force has advised us that Individuals will be transported outside of Hampshire for processing in the normal way after they have been safely disembarked.'