MANCHESTER'S representatives on the Board of Deputies have threatened to resign.
They say they will do this if Yachad, the pro-peace movement, becomes a member on Sunday.
The Manchester deputies could even set up their own rival pro-Israel umbrella organisation.
Stunned delegates only received their agendas, tabling the recommendation of approval of Yachad's membership, on Wednesday evening.
They were also informed that the London meeting had been scheduled for 11am instead of the original 2.15pm because of Sunday's pro-Israel rally there.
Last year, the Zionist Federation turned down Yachad's membership application because of its critical attitude to Israel.
Manchester Zionist Central Council president Raymond Solomon, who is also a BoD deputy for Cheetham Hebrew Congregation, told the Jewish Telegraph: "All Yachad do is criticise Israel. Even though their website says they are pro-Israel, their actions do not back that up."
He added: "I am also disgruntled with the Board for giving us such little time to attend. People in the regions will find it very difficult to get there on time."
BoD president Vivian Wineman said he had not received Mr Solomon's complaint and explained that the vote would take place at the end of the morning meeting to enable regional delegates to arrive in time.
But Mr Solomon warned that should Yachad's membership be accepted, he would resign and consider setting up a breakaway organisation.
Deputy for Bury Hebrew Congregation Raymond Cook told the Jewish Telegraph: "Although Yachad purports to be a pro-Israel organisation, it spends all its time highlighting Israeli infringements of human rights without giving the other side of the story."
He accused Yachad of "trying to force a wedge into the UK Jewish community".
Yachad director Hannah Weisfeld said: "There are many in the community who support our work. We want their views heard. People are entitled to disagree but it is a democratic body. Why should our supporters not be represented?"