Controversial Liberal Democrat MP David Ward could be stripped of the party whip for his offensive tweets about Jews and Israel, according to the party's most senior Jewish minister.
Crime Prevention Minister Lynne Featherstone said the Bradford East MP was treading a thin line with his regular attacks on social media.
He briefly lost the party whip following disciplinary action in 2013 after posts targeting Jews and Zionists.
"He might lose it again if he's not careful. There's a thin line between free speech and hate speech and incitement," Ms Featherstone told the JC.
"Obviously, the party takes these matters very seriously. It won't be tolerated. When that line is overstepped then I expect party officials to step in."
We should be able to have a debate on Israel without the polarisation
Ms Featherstone called for a "grown up" debate on peace between Israel and the Palestinians, and said both sides must recognise the level of concession needed.
The Home Office minister said: "I'm critical of both sides. Every time there is an incident you are shouted at - that's not terribly constructive.
"We should be able to have this debate, and say things about Israel and the West Bank or Gaza without the polarisation that happens around every mention of the Middle East."
During last summer's Gaza conflict, Lib Dem Business Secretary Vince Cable pushed for an arms embargo on Israel, leading to criticism from the Israel embassy.
Ms Featherstone said: "Israel makes it very difficult with the settlements - it's difficult to argue their case in the way we used to be able to argue for Israel.
"It's a difficult issue, just as the rockets into Israel are unforgivable. It can only be solved by talking and inclusiveness and a political solution. Threats and boycotts are not the way."
Speaking in detail about her own beliefs for the first time, Ms Featherstone said she was already "going astray" from Judaism before her
religious father died when she was 15.
Her sister had lived for a time in Israel and continued to host family meals at Pesach. "I go round to her for Passover seders, I enjoy those customs and the family things that go with it," Ms Featherstone said. "I will always be Jewish - that's what I am and where I came from. I don't practise. I like integration and I think it goes well with being a liberal."
The Hornsey and Wood Green MP's ministerial portfolio has led her to be one of the government's leading voices on domestic abuse, sexual violence and female genital mutilation (FGM).
"I've made this my mission," she said. "If they were cutting off half of boys' penises it wouldn't last four minutes, let alone 4,000 years."
Within British Jewry, there was a reluctance to report domestic abuse to the police, she suggested. "People must acknowledge it themselves. Make something public. Use the law."
The 63-year-old minister would be well-placed for another key role if the Lib Dems return to power after the election. But she said she had no intention of replacing Nick Clegg if he loses his position as leader.
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