Andy McDonald has been suspended as a Labour MP, after the party said he had made “deeply offensive” comments relating to the Israel-Gaza war.
The MP for Middlesbrough used the phrase “between the river and the sea” in a speech at a pro-Palestinian rally.
Critics of the chant argue it implicitly calls for the destruction of Israel, although pro-Palestinian protesters have contested this.
He will now sit as an independent MP, pending an investigation.
In his speech at a demonstration on Saturday, Mr McDonald said: “We will not rest until we have justice. Until all people, Israelis and Palestinians, between the river and the sea, can live in peaceful liberty.”
The phrase “from the river to the sea” refers to the land between the River Jordan and the Mediterranean.
Earlier this month, Home Secretary Suella Braverman urged police chiefs to consider interpreting the chant as an “expression of a violent desire to see Israel erased from the world”. Israel and most Jewish groups agree.
This interpretation is disputed by some pro-Palestinian activists who say that most people chanting it are calling for an end to Israel’s occupation of the West Bank and blockade of Gaza, not the destruction of Israel itself.
When asked about the chant in a briefing with reporters earlier, Prime Minister Rishi Sunak’s spokesman said: “We understand clearly this is a deeply offensive chant to many.”
A Labour spokesperson said Mr McDonald’s comments at the weekend “were deeply offensive, particularly at a time of rising antisemitism which has left Jewish people fearful for their safety”.
“The chief whip has suspended the Labour whip from Andy McDonald, pending an investigation,” the spokesperson said.
Momentum, a left-wing Labour campaign group, branded Mr McDonald’s suspension “an appalling and opportunistic attempt from the Starmer leadership to silence those speaking out in solidarity with Palestine”.
The group said Sir Keir had “joined in with disingenuous smears put out by the right-wing press, which deliberately misrepresent Andy’s call for peace”.
More on Israel-Gaza war
Mr McDonald’s suspension follows days of internal Labour tensions over the party’s position on the Israel-Gaza war.
Labour leader Sir Keir Starmer has not called for a ceasefire, instead backing humanitarian pauses to help aid reach Gaza.
In stopping short of backing a full ceasefire, the Labour leader is aligned with the UK government, as well as the US and EU.
But dozens of Labour councillors, and senior figures including mayors Sadiq Khan and Andy Burnham, and Scottish Labour leader Anas Sarwar, have called for a formal ceasefire.
The Conservatives have had their own party discipline issues over the Israel-Gaza war, with a ministerial aide earlier being sacked from his government role after calling for a ceasefire.
Earlier, Israel’s Prime Minister Benjamin Netanyahu told a press conference his country “will not agree to a cessation of hostilities with Hamas”.
“Calls for a ceasefire are a call for Israel to surrender to Hamas,” Mr Netanyahu said.
Hamas gunmen killed 1,400 people in an unprecedented attack on southern Israel on 7 October.
Gaza’s Hamas-run health ministry says more than 8,300 people have been killed in the territory since then, after Israel launched a war intended to destroy Hamas.
