Shadow chancellor John McDonnell has waded into the row over outspoken Labour leadership critic Luciana Berger, who is facing a vote of no confidence by her local constituency party.
Mr McDonnell said he understood the action against Ms Berger was triggered by concern the MP could join a breakaway party, not because she has criticised Jeremy Corbyn's stance on anti-Semitism.
- Read more: John McDonnell: ‘I thought Remain would win the referendum'
- Read more: John McDonnell refuses to deny he wants to 'overthrow capitalism'
Ms Berger, who is Jewish, has been highly critical of Mr Corbyn over his handling of anti-Semitism within the Labour Party, as well as his positioning on Brexit.
Senior Labour MPs have rallied behind Ms Berger after it emerged the Liverpool Wavertree Constituency Labour Party had called an extraordinary meeting for February 17 to discuss two no-confidence motions.
Mr McDonnell has called on the MP to make clear she is not planning to "jump ship".
'She should put this issue to bed'
The shadow chancellor told Sky News: "If people are saying 'look, we are expressing a vote of no confidence because Luciana has stood up and exposed anti-Semitism in our party', that would be completely wrong and, of course, we would say that is not right.
"But it looks as though there's other issues.
"It seems on social media, from what I've seen, what's happened is Luciana has been associated in the media with a breakaway party.
"Some local party members, the media, have asked her to deny that. She hasn't been clear in that.
"So my advice really, on all of this, is for Luciana to just put this issue to bed.
"Say very clearly 'no, I'm not supporting another party, I'm not jumping ship'.
"And for local party members to sit down with Luciana and actually say 'how can we support you? How can we work together in the future?' And then overcome the present difficulties."
Mr McDonnell said: "It's not a deselection from what I understand. We are not into our selection process.
"It's a vote of no confidence, which is simply an expression by local party members."
Ms Berger's stance on anti-Semitism has seen her face a torrent of abuse from online trolls and she required a police escort at last year's Labour Party conference after receiving death threats.
The move against Ms Berger comes after she joined other MPs at a meeting of the Parliamentary Labour Party on Monday in calling for details on the party's efforts to tackle anti-Semitism to be released.
Mr McDonnell's comments drew criticism from some Labour MPs.
Chuka Umunna said there should be pressure put on Ms Berger's Constituency Labour Party (CLP) to treat the MP with respect.
Mr Umunna tweeted: "So a victim of outrageous racism in @UKLabour must promise she will not walk because of that racism and then this can all go away.
"How about demanding her CLP treats her with the respect she deserves. How about the party deals with that racism. Words fail me. Totally unacceptable."
Shadow education secretary Angela Rayner offered Ms Berger her backing for speaking out against anti-Semitism when asked on Twitter by Mr Umunna what she thought of the situation.
Ms Rayner tweeted: "I don't know what's happening in Luciana's constituency but she has my full support in speaking out and stamping out the racism and antisemitism that's in our party & wider community."