Tens of thousands of people marched through central London on Saturday in two separate protests - one against high levels of immigration and a perceived Islamic threat to British identity, and another in support of Palestinians.
Police deployed 4,000 officers, including reinforcements from outside the capital, and pledged "the most assertive possible use of our powers" in what they called their biggest public order operation in years.
By 3:30 p.m. local time, about four hours after both marches started, police said they had made 31 arrests for a range of offenses and described both protests as "largely without significant incident." They had earlier forecast turnout of at least 80,000.
Prime Minister Keir Starmer on Friday accused organizers of the Unite the Kingdom march of "peddling hate and division, plain and simple."
The march was organized by anti-Islam activist Stephen Yaxley-Lennon, known as Tommy Robinson. The government barred 11 people it described as "foreign far-right agitators" from entering Britain to address the protest.
Pro-Palestinian, anti-Immigration protests draw thousands to London
A previous protest led by Robinson in September drew around 150,000 people, police said, and featured a video address by US tech billionaire Elon Musk. Scuffles left 26 officers injured, including four seriously.
On Saturday, Robinson supporters gathered in central London, waving mainly British and English flags.
"I think that too much migration – not migration, but too much migration – is causing a lot of problems, upsetting a delicate balance here," said Allison Parr, who also criticized net-zero environmental policies.
Annual net migration approached 900,000 in 2022 and 2023, but fell back to around 200,000 last year after tighter work visa rules.
Concern over immigration - including the arrival of asylum seekers on small boats - has weighed on Starmer's popularity and boosted the right-wing Reform UK party, whose leader Nigel Farage has distanced himself from Robinson.
Some protesters chanted abuse about Starmer.
Robinson, who has convictions for assault, stalking, and other offenses, said during the march that "we are awakening Great Britain - the cultural awakening, the cultural revolution, the spiritual awakening, it's all underway."
Earlier this year, he traveled to the US, where he met a State Department official and addressed supporters about what he called "the dangers of Islam" and "the Islamification of Great Britain."
Census data showed 6.5% of people in England and Wales identified as Muslim in 2021, up from 4.9% in 2011.
Among those on the main stage at the end of the march were three French women from the anti-immigration feminist group Nemesis. They appeared wearing Islamic-style face veils and encouraged jeers before removing the veils to whoops from the crowd, and gave a short speech critical of Muslims and immigration.
Later, a cellist performed with what appeared to be rashers of raw bacon on his shoulders.
Nearby, demonstrators carrying Palestinian flags and placards calling for an end to the conflict in Gaza held a march to mark Nakba Day, commemorating Palestinians' loss of land in the 1948 war that followed the creation of Israel. "Nakba" means catastrophe in Arabic.
"Israel, its behavior is unjust beyond belief," protester Sharon De-Wit said. "After the Holocaust, etc., all you can do is wish the Jewish people all the best. But they won't be able to live in peace until they allow the Palestinian people to form their own state."
London has recently seen a spate of arson attacks on Jewish sites, and two Jewish men were stabbed last month in an incident being treated as terrorism.
Police said repeated large pro-Palestinian marches - 33 since the Hamas-led attack on Israel in October 2023 - had left many Jewish people feeling too intimidated to enter central London.
While protesters held a range of views, police said the marches routinely led to arrests for racially and religiously aggravated public order offenses.
Some protesters on Saturday chanted "Death to the IDF," referring to the Israeli army - language that police previously said had been a reason for arrests when aimed at Jewish people.