Former MEP candidate for the Green Party Saoirse McHugh says she has left the organisation.
Ms McHugh has previously said she would resign from the party if they went into coalition with Fine Gael or Fianna Fáil.
In a series of tweets on Thursday, she heavily criticised the Programme for Government and her former party.
She said: "The reasons I have left are obvious, I joined the Greens with the hope of furthering the cause of climate justice.
"The [Programme for Government] that has been agreed on is a terrible document.
"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 peoples lives will support for climate action be ensured".
She added: "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".
She also expressed her hope that an affiliate group of the Green Party would 'break off and form an actual eco socialist party', adding that she "couldn’t stomach being affiliated with the Greens".
"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 was a candidate for Midlands-North West in the European elections last year, but failed to get elected.
