The left-wing Scottish Greens party expelled 13 of its members on Saturday for signing a declaration that stated "sex is a biological reality."

The declaration, which was released in November of last year, also stated that women have the right to maintain sex-based protections enshrined in the Equality Act and that "women and girls have the right to discuss policies which affect them without being abused, harassed or intimidated."

"We know that globally women, as a sex, are disproportionately affected by climate change and environmental degradation, and that their empowerment is essential to our work as environmentalists," it stated. 

Those who signed the declaration were subsequently reported to the Conduct and Complaints Committee (CCC) which led to a disciplinary investigation, per Daily Mail. Those who complained included members of the Rainbow Greens, an LGBTQ+ branch of the Green political parties. They accused the signers of bullying, "behaviours that constitute prejudice based on sexual orientation or gender identity," and "behaviours that constitute a threat to others."

The party decided that the members who signed the declaration posed a risk to the "safety of all trans and non-binary members," per The Telegraph, and the CCC expelled them with immediate effect. In 2018 the Scottish Greens set forth a rule that stated “trans-exclusionary individuals of any kind are not welcome as members."

However the party's former co-leader Robin Harper called the expulsion "utterly laughable," adding that there was nothing in the statement that was "aggressive or critical" towards trans people and called for current leaders Patrick Harvie and Lorna Slater to be ousted after a confidence vote.

“The party needs to get together and lodge a vote of no confidence in the current leadership,” Harper stated. "People should stay in and try to reform the party from the inside, and have the courage to do so."

One of the expelled members, David Jardine, also spoke out against the decision. “All that it did was assert the right of women to advocate for a series of eight beliefs that they had,” he said. “It wasn’t a demand that the party overturn policy, merely that people be allowed to speak without being harassed and pressurised.”

A spokesman for the Scottish Green Party said: “We can confirm disciplinary action was taken against 13 individuals over a breach of our membership policy, which has resulted in their immediate expulsion from the party.

“The welfare of all our members is our primary concern. The CCC [conducts and complaints committee] process found that the members were in breach of our code of conduct.

“Next month is Pride month and we hope this decisive action will send a clear message that we stand in solidarity with the LGBTQ+ community now and forever.”