The Greens party room is considering expelling New South Wales senator Lee Rhiannon because she has already been censured twice for breaking party rules.
The federal party's nine other senators and MPs are furious with Senator Rhiannon for what they argue was deceptive conduct over the Government's school funding legislation.
Senator Rhiannon is accused of breaking the Greens party rules and acting in bad faith by failing to tell her colleagues that she had decided to campaign and vote against the bill, while other senators were still in official negotiations with the Government.
A Greens partyroom meeting via teleconference today did not reach a decision on what, if any, punishment should be imposed, and another meeting is likely to be held this week.
But the ABC understands that the extraordinary step of expulsion from the party room is being considered, because previous censures have not changed Senator Rhiannon's behaviour.
Even if Senator Rhiannon was expelled from the party room she would remain a Greens member.
Senator Rhiannon has denied that she thwarted the Greens negotiations with the Government over school funding.
"It was the Turnbull Government's decision to do a deal with the crossbench senators that killed off negotiations with the Greens," she said in a statement.
"At all times my actions on education have been faithful to the Greens policy and process."
The Greens Left Renewal faction has also expressed its dismay at the treatment of Senator Rhiannon.
"We are disappointed in the party room's eagerness to cruelly and publicly undermine NSW's Greens senator for simply taking the position of her party, and a policy the Greens took to an election, into parliament," it said in a statement.
