Rishi Sunak has declared there is no acceptable “context” to beam “antisemitic tropes onto Big Ben”.
The Prime Minister, in a message to pro-Palestine protesters, said “you can march and protest with passion”.
“But no, you cannot call for Jihad”, the Prime Minister said.
Activists sparked fury after projecting from the river to the sea onto Parliament’s Elizabeth Tower.
Thousands of protesters had descended onto Parliament Square for a rally on Wednesday night amid farcical scenes in the House of Commons.
And the Prime Minister declared tonight, at the Community Security Trust annual dinner: “There is no “context” in which its acceptable to beam antisemitic tropes onto Big Ben.
“And there’s no cause you can use to justify the support of proscribed terrorist groups, like Hamas.
“And yes, you can freely criticise the actions of this government, the Israeli government or indeed any government.
“But no, you cannot use that as an excuse to call for the eradication of a State – or any kind of hatred or antisemitism.”
“These statements are fundamental to the liberal democratic values that define Britain.
“They are the very essence of our identity of who we are as a country.
“To belong here is to believe these things; to stand up for these things.
“And it’s time we were much, much clearer about this.”
Mr Sunak also insisted university leaders “must take personal responsibility” for the safety of Jewish students on campuses.
He said: “What is happening right now on campuses is simply not acceptable.
“Jewish students are being targeted, threatened, and assaulted simply for being Jewish.
“The Chaplain at the University of Leeds having to take his family into hiding after death threats because he’s an IDF reservist.
“Iranian generals – let me say that again – Iranian generals – giving antisemitic speeches as people abuse the right to freedom of speech as a cover for hate speech.
“This cannot go on.”
