Green Party activists are plotting to oust former party leader Caroline Lucas, according to reports.

Party members have accused Ms Lucas, who was the party’s first MP when elected in 2010, of being “toxic, divisive and a shill for apartheid and genocide”, reports The Telegraph.

It is alleged that WhatsApp messages sent between members contain advice on how to submit complaints to the party’s disciplinary panel about Ms Lucas, with the hope that enough complaints could encourage the party to act against her.

It comes after Greens for Palestine orchestrated a campaign to pass a motion defining Zionism as racism, with some senior moderate Greens claiming the party has succumbed to entryism.

The motion called for the abolition of the state of Israel, and defined the right to Jewish self-determination as a racist ideology.

It was passed at the party’s conference earlier this month by 1,022 votes to 813, and thus became policy despite having the backing of less than 1% of the Greens’ membership.

The Green party’s membership has more than trebled over the past year - from around 60,000 last September to around 230,000 now.

Ms Lucas said it had been a mistake for Mr Polanski to miss the vote, adding that the party was “woefully exposed” to entryism.

She also called for Lubna Speitan, the policy’s author, to be suspended due to her links to an al-Qaeda terrorist who plotted to bomb passengers landing at Heathrow from Israel.

At the party conference, Ms Lucas warned that a “refusal to accept complexities” about the region had led to many Jewish Greens feeling unsafe and unwelcome.

In WhatsApp messages seen by the Telegraph, activists described Ms Lucas’s comments as “despicable”, with one writing: “Lucas needs to be removed. She’s toxic, divisive and a shill for apartheid and genocide.”

Members argued that Ms Lucas should be expelled for bringing the party into disrepute, with others disputing whether she still had a formal role within the party.

In other messages, the Greens for Palestine group attacked Ms Lucas for her criticism of the Zionism is Racism policy.

Ms Lucas told BBC Newsnight that the motion was “dangerous”, “divisive” and “flawed from top to bottom”.

Under party rules, the Greens can not “significantly” amend the Zionism is Racism policy until 2028, unless Mr Polanski intervenes.

The party has been referred to the Equality and Human Rights Commission by the Campaign Against Antisemitism (CAAS), which branded the motion “brazenly discriminatory”.