Saoirse McHugh has announced her departure from the Green Party this morning.
The Mayo native stood for the party in last year's European elections and the 2020 general election but did not gain a seat in either.
However, she did not back the programme for government and previously revealed she would leave the party if they entered government.
She broke the news of her decision on Twitter, revealing that her concerns about the programme for government and climate justice had been the main factors in her decision.
Ms McHugh said she "couldn't stomach" remaining as a a party member.
Slamming the programme for government as a "terrible document", the Achill Islander said: "The membership were told it contained certain things that it didn’t.
"This government, I believe (and I hope I’m wrong) will do massive damage to the idea of environmentalism by linking it with socially regressive policies.
"Only by viscerally improving people's lives will support for climate action be ensured. Our problems in housing, tax avoidance, healthcare, agriculture etc are inextricably linked with and reinforce environmental breakdown and because of this, solutions must be mutual."
Ms McHugh added that while she would not be joining a breakaway group the Just Transition Greens, she "supports and understands" what they are doing.
She added: "I don’t believe that our pathway to a just and free society lies in electoral politics.
"I have seen how brilliant and brave people are bullied and silenced within parties that profess to be grounded in equality and democracy.
"I’ve seen how much effort and energy gets taken up by elections and internal party struggles.
"Our only way forward is climate justice and that’s what I will continue to work towards but the Greens no longer provide a vehicle to do that."
Ms McHugh concluded: "I do hope I’m mistaken and I hope this government exceeds all expectations. I’d happily be proven so wrong!"
