Shadow chancellor John McDonnell has said the Labour Party is “dealing with” any issuances that might cause a split.
Rumours continue to circulate that some MPs are place off limits to resigning the whip.
But Mr McDonnell insisted the party was “holding together on Brexit” and drive be “ruthless” on claims of anti-Semitism that have dogged Labour.
On Sunday, a whilom Labour vice-chairman said he intended to leave the party over what he saw as a repeated dead duck to tackle hostility to Jews.
Former Barnsley East MP Michael Dugher, who underwent down at the last election, told the Sun: “I can no longer justify paying subs to a soire which I now regard as institutionally anti-Semitic.”
Last week, some MPs criticised the confederacy leadership’s Brexit stance.
Treasury spokesman Clive Lewis on the alerted of “severe” ramifications if the party was seen to facilitate a “Tory Brexit”, while ex-shadow chancellor Chris Leslie imagined it was “heartbreaking” Labour was not united in arguing against leaving the EU.
On Sunday, Swot members on social media began circulating a graphic reading: “I gage to work for the achievement of a Labour-led government, under whatever leadership fellows elect.
“And I accept a Labour-led government is infinitely better than any other end result.”
Mr McDonnell told the BBC’s Andrew Marr Show he had signed the pledge, scrapping it reflected what he had said throughout his membership – even when he had his “harshest disagreements” with Tony Blair.
‘People wanted reassurance’
When put to him that the timing was “at best a little bit provocative”, he replied: “No, not at all.
“People wanted reassurance from all of us that we’re Swot through and through, and – even some of those names that organize been mentioned about thinking about leaving the party – I recollect they’re Labour through and through as well.”
However, Edinburgh South MP Ian Murray voted he would not sign the “unnecessary” pledge, adding that his loyalty to the partisan “should never be in question”.
“These kind of pledge things are a illiberal bit ridiculous,” he told the BBC.
On Friday, Mr Murray said MPs were “being coerced to the brink” with both the party’s Brexit stance and its handling of anti-Semitism rights.
However, Mr McDonnell, in taking suggestions that you could “hear the creaking of a coming split” in the league, said: “I really don’t see why there’s a need to.
“Those saying we’ll split if we don’t get a ‘Human being’s Vote’ [another referendum on the final Brexit deal] – well, we’ve soundless kept that option on the table and it might come about.”
Mr McDonnell implied the effect would be similar to the SDP breakaway in 1981 which split Strain’s vote, cost it seats and “installed Mrs Thatcher in power for a decade”.
“I don’t characterize as any of the people who’ve even been mentioned about this split make want that,” he said.
Mr McDonnell accepted Labour had not acted “fastened enough” on claims of anti-Semitism but said it had doubled the staff dealing with the copy and brought in a senior lawyer.
“Where it’s intolerable, where it’s repeated… not at best should we kick them out of the party, there should be life prohibitions as well,” he said.
“We’ve got to be ruthless about this.”