More than 50 British Labour party members have been suspended in the past two months over comments deemed racist or anti-Semitic, according to The Daily Telegraph, including former mayor of London Ken Livingstone.
After the latest suspensions of three local councillors on Monday over comments posted on social media, a spokesman for the Israeli party said breaking off relations with British comrades was "one of the options that is being considered."
He told AFP that the Israeli party was looking for assurances from British Labour leader Jeremy Corbyn that he was treating the allegations with the necessary gravity.
In the most high-profile case, the former London mayor was sanctioned on Thursday after saying that Adolf Hitler "was supporting Zionism before he went mad and ended up killing six million Jews".
Livingstone's comments were in defence of Labour MP Naz Shah, who was suspended last Wednesday for sharing posts on social media two years ago suggesting that the solution to the Palestinian conflict was to move Israel to the United States.
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Corbyn has announced an independent review into the allegations, saying there was no place for "anti-Semitism or any form of racism in the Labour Party."
The dispute has been simmering for months -- ever since the left-winger was elected party leader by grassroots supporters last September despite opposition from many MPs.
Corbyn has been criticised in the past for referring to Lebanese Shiite militant group Hezbollah as "friends" and urging dialogue with Palestinian Islamist movement Hamas, as well as meeting representatives of both organisations.
Israeli lawmaker Oren Hazan of the ruling right-wing governing Likud party said Corbyn ought to focus on the "real front of Islamic terrorism playing a lead role in Europe... instead of focusing on a peace-seeking country like Israel."
The head of the opposition Yesh Atid party, former finance minister Yair Lapid, said: "The disease of antisemitism has taken root inside the British Labour Party and the leadership seems both incapable and unwilling to tackle the problem."
The Israeli foreign ministry and Prime Minister Benjamin Netanyahu's office declined to comment, saying it was a domestic British issue.