The french Socialist Party is due to sack four Jewish MPs as part of a coalition deal with the Green Party ahead of next year's elections.
The Socialists and the Greens signed an agreement last month to back one candidate per constituency for the 2012 National Assembly poll.
In order to fulfil its side of the bargain, the Socialist party will fire Serge Blisko, Tony Dreyfus, Daniel Goldberg and Danièle Hofman, who all hold seats in the Paris area.
Richard Prasquier, president of CRIF, the umbrella body for French Jewry, said: "This list of dismissals is disastrous. It would be tempting to see antisemitism here. The Greens have made their loathing of Israel one of their headline messages.
"The choice made by the Socialist Party will be perceived by the Jewish community as going in the same direction."
One of the four MPs on the list, who asked to remain anonymous, said: "One could feel it coming. When the Socialist Party recently issued a statement in favour of the immediate recognition of a Palestinian state, only a handful of MPs refused to sign it. I did not sign it. The others who didn't are on the same list."
The ousting of the four, if confirmed next year, will mark the end of a golden era. The Socialist Party was a staunch supporter of Israel until the end of the 1970s because the Zionist movement was regarded as being socialist. The first major crack appeared in March 1982 when then-President Francois Mitterrand - a Socialist - addressed the Knesset and spoke on behalf of the creation of a state of Palestine.
During Mitterrand's 14 years in power, young Socialists were raised with the new pro-PLO ideology. The rift between the pro- and anti-Israel sections of the party widened. Many young Socialists started to agree with the extreme-left vision of Israel as a remnant of a colonialist past.
The four Paris MPs have a long record of supporting Israel in one way or another. Being Jewish might be purely coincidental. But by taking this decision, the leaders of the Socialist Party have signalled that a page of history has been turned.