Under fire from opposition lawmakers and members of his own governing Conservative Party to eject Braverman, Sunak moved against his interior minister, asking her "to leave government" which she had accepted, the source said.
The political editor of the Sun tabloid said Foreign Secretary James Cleverly would replace her. As Sunak started to reshuffle his ministerial team, former prime minister David Cameron was seen walking into Downing Street, sparking speculation that he would return to government.
Last week, Braverman defied Sunak by publishing an article accusing the police of adopting "double standards" in its treatment of protests - an argument opposition Labor said inflamed tensions at a pro-Palestinian demonstration on Saturday.
Then more than 140 people were arrested after far-right counter protesters skirmished with police, who tried to keep them away from the 300,000 pro-Palestinian marchers.
Sunak is expected to carry out a wider number of changes in his cabinet, bringing in allies and removing some ministers who his Downing Street office say have not been performing as well as he wanted in their departments.
Hundreds of thousands of demonstrators rallied in cities in Europe, the Middle East and Asia on Saturday to show support for the Palestinians as Israel's military widened its air and ground offensive on the Gaza Strip.
In one of the biggest marches, in London, aerial footage showed large crowds marching through the centre of the capital to demand the government of Prime Minister Rishi Sunak call for a ceasefire
"The superpowers at play are not doing enough at the moment. This is why we're here: we're calling for a ceasefire, calling for Palestinian rights, the right to exist, to live, human rights, all our rights," said protester Camille Revuelta.
"This is not about Hamas. This is about protecting Palestinian lives," she added.
Echoing Washington's stance, Sunak's government has stopped short of calling for a ceasefire, and instead advocated humanitarian pauses to allow aid to reach people in Gaza.
Britain has supported Israel's right to defend itself after the Oct. 7 attack by militant group Hamas that Israel said killed 1,400 people, mostly civilians.
The death toll in Gaza has climbed to 7,650 dead, also mostly civilians, since Israel's bombardment began three weeks ago, according to a daily report released on Saturday from the Palestinian health ministry.
There has been strong support and sympathy for Israel from Western governments and many citizens over the Hamas attacks, but the Israeli response has also prompted anger, particularly in Arab and Muslim countries.
In Malaysia, a large crowd of demonstrators chanted slogans outside the US embassy in Kuala Lumpur.
Addressing hundreds of thousands of supporters at a huge rally in Istanbul, Turkish President Tayyip Erdogan said Israel was an occupier, and repeated his stance about Hamas not being a terrorist organisation.
Erdogan drew a sharp rebuke from Israel this week for calling the Palestinian group "freedom fighters".
Iraqis took part in a rally in Baghdad and in the Israeli-occupied West Bank, Palestinian protesters in Hebron called on Saturday for a global boycott of Israeli products.
"Don't contribute to the killing of the children of Palestine," they chanted.
Elsewhere in Europe, people took to the streets of Copenhagen, Rome and Stockholm.
Some cities in France have banned rallies since the war began, fearing they could fuel social tensions, but despite a ban in Paris, a small rally took place on Saturday. Several hundred people also marched in the southern city of Marseille.
In New Zealand's capital, Wellington, thousands of people holding Palestinian flags and placards reading "Free Palestine" marched to Parliament House.
In London, special restrictions were in place restricting protests around the Israeli Embassy.
Saturday's march was peaceful, but police said they had made two arrests, one along the march route after a police officer was assaulted and another on suspicion of a racially aggravated public order offence after a man was heard shouting racist remarks.
Police estimated the turnout at between 50,000 and 70,000 people.
London police have faced criticism in recent days for not being tougher over slogans shouted by some protesters during another pro-Palestinian march in the capital last week, which drew about 100,000 people.
