Sir Keir Starmer was surrounded by frustrated Palestine protesters after making a speech defying calls fora ceasefire in Gaza.
The Labour leader said he understands the demand but argued it was not the "correct position" at the moment.
Following his speech, Starmer was bombarded with crowds of pro-Palestine campaigners outside Chatham House in London before police intervened and he was bundled into a car.
Protesters shouted at the Labour leader and demanded an immediate ceasefire in Gaza.
Police officers pushed people aside, however some campaigners ran at the car and banged on the windows.
The incident happened after Starmer addressed an audience where he insisted his stance of calling for a humanitarian pause was "the only credible approach".
He said that freezing the situation in its current state would do nothing to free the hostages taken by Hamas.
The Labour Party has already received backlash following the suspension of an MP over what the party described as "deeply offensive" comments at a pro-Palestinian rally.
LATEST PALESTINE PROTESTS:
The Labour leader was mobbed after giving his speech
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Andy McDonald was criticised after using the controversial slogan “from the river to the sea” to share his backing for Palestine over the weekend.
During the rally, he said: "We won't rest until we have justice. Until all people, Israelis and Palestinians, between the river and the sea, can live in peaceful liberty."
Downing Street condemned the use of the phrase - referring to the land between the River Jordan and the Mediterranean Sea - as "not acceptable".
The phrase is often associated with an antisemitic chant about eradicating Jews.
The activists demanded Sir Keir Starmer support a ceasefire in Palestine
PA
Last night McDonald said he was "saddended" by his suspension but was confident that he would be readmitted to the Parliamentary Labour Party.
He said: "These words should not be construed in any other way than they were intended, namely as a heartfelt plea for an end to the killings in Israel, Gaza, and the occupied West Bank, and for all peoples in the region to live in freedom without the threat of violence.
"I will be happy to explain these views to the investigation when it convenes and trust that the whip will be restored.
"In the meantime, for the sake of humanity, I hope and pray that we see an end to the war in Gaza, and steps are taken towards a lasting peace."
