The Green Party is at a "crossroads" and needs to focus on its "core values", a former party co-leader has told the BBC, weeks after members adopted a motion declaring Zionism a form of racism.
Adrian Ramsay suggested the Greens need their policies to appeal to a majority of British voters if they want to bring the "environmental changes that we need" and advised against taking an approach that risks being "quite divisive".
Green Party leader Zack Polanski responded by saying there was "no environmental justice without social, racial and economic justice".
The motion, which Polanski did not take part in or vote upon, defined Zionism as an ideology supporting "an ethnonationalist Jewish state" that had led to the "disenfranchisement and destruction" of Palestinians.
It backed the creation of a "single democratic Palestinian state in all of historic Palestine", which includes modern-day Israel.
Members of the Green Party of England and Wales adopted the policy motion last month.
It led to a backlash from some Jewish groups, as well as criticism from senior Green figures, including Ramsay and other Green MPs.
Israel's foreign ministry said it had banned Polanski, who is Jewish, from entering the country.
The Equality and Human Rights Commission also wrote to the Green Party asking for more information about the motion after concerns were raised by dozens of Labour and Lib Dem MPs and Jewish campaigners.
Labour later said it would end power-sharing agreements with the Greens on local councils, unless its councillors disowned the policy.
Speaking to Newscast, Ramsay replied "no, it's not" when asked if he thought Zionism is racist before adding he agreed with Polanski and others in believing that what is happening in Gaza is "appalling".
The MP for Waveney Valley, who joined the party in 1998, said he does think Israel has a right to exist, something Polanski has stopped short of saying.
Ramsay also said he has made it clear he is "deeply uncomfortable" with the motion adopted and suggested there is an "opportunity to take some action in relation to the motion in the run-up" to the party's spring conference next year.
He said the question now is how Polanski and the party as a whole responds to the motion.
Ramsay said: "I think there's a real crossroads point for the party at the moment.
"One option is to sort of dig in more down this approach, not only in relation to this motion, but I think that there's a risk it brings with it - a quite divisive, a quite internally focused approach to politics."
Ramsay said this is "perhaps seen from small groups of people on the hard left of politics who go around different parties try to influence how those parties are run".
He added: "What I want to see is the party really focus back in on our core aims as a party and our core values."
Ramsay said this includes ensuring the party is "consensus-building in how we approach our politics" and that "we engage the grassroots of our membership".
He added the party needs to be "very externally focused, because we're only going to be able to bring the environmental changes that we need to have to safeguard our society for now and for the future if the majority of the British public come behind that".
Polanski, who missed the conference vote to unsuccessfully campaign for election in a Westminster by-election, previously said he wants to see the "imperfect" motion amended in future.
However, he said the "substantial part of the motion", that "the displacement and genocide of the Palestinian people is clearly underpinned by a racist ideology" was "obvious". Israel has repeatedly denied its actions in Gaza amount to genocide.
Under Green Party rules, motions supported by members become official party policy, but will not necessarily be included in the party's manifesto at the next general election.
