Labour's deputy leader has warned his party to "calm down" amid growing speculation that a leadership challenge is brewing.
Tom Watson warned MPs that party voters would not want to see Jeremy Corbyn challenged nine months after he swept to success with a huge mandate.
There are fears among Mr Corbyn's supporters that moderates could seek to oust him if Labour continues to struggle in the polls.
Speaking on Sky News' Murnaghan Show, Mr Watson said: "This is the great irony of politics in that there are people within the party trying to change the rules in order to try and protect Jeremy's position and they might just be precipitating the challenge to his leadership.
"Of course that's just not common sense and I hope those people who are holding those different point of views calm down a bit.
"The fundamentals are both Jeremy and I were elected last September on a very large mandate from our membership, they decided who the leader and deputy leader are and they do not want after nine months another leadership challenge and I hope that those MPs on all sides of this argument will pay heed to that."
He criticised Ken Livingstone for aiding divisions in the party by comparing Labour MP Dan Jarvis to Jimmy Savile in a recent interview with BBC News.
The former London Mayor, an ally of Mr Corbyn, said Mr Jarvis' acceptance of a hedge fund donation was like "Jimmy Savile funding a children's group".
Backbencher Mr Jarvis has been tipped as a possible rival to Mr Corbyn's leadership after he called for the party to be "more radical than ever before" in tackling inequality.
Mr Watson said: "I was incredibly disappointed by that and I know Jeremy is too.
"That was very unhelpful. What we're trying to do is make sure all our members and MPs stick to talking about policies and issues and don't slug it out with personal insults."
Meanwhile Labour MP John Mann said there is resurging problem with anti-Semitism within the party, including on the left, which must be stamped out.
He said the recent growth of the party membership, sparked by left-winger Mr Corbyn's leadership win, has brought with it some people with "out-dated and prejudiced" views.
The Parliamentary Labour Party is currently carrying out an investigation in to anti-Semitism in the Oxford University Labour Club.
Asked by Andrew Neil on the BBC's Daily Sunday Politics if there was a clear anti-Semitism problem within Labour, Mr Mann said: "Of course there is. That's why these issues have got attention. It's not a big problem but a small problem when it comes to racism needs to be dealt with."
"The atmosphere that's been created at Oxford University is not a one-off. This has been happening elsewhere as well."
The chair of the all-party parliamentary group against anti-Semitism, added: "People have been accustomed to the Labour Party and that part of the left being highly tolerant to everybody, that has to happen.
"You cannot have a progressive party of any substance in politics if it allows any form of intolerance and therefore we're not prepared to have second class citizens, a second-class form of racism allowed in the Labour Party.
"Anti-Semitism has to be challenged, including anti-Semitism on the left and done so robustly."