Greens senator Lee Rhiannon has angrily rejected claims she derailed her party's school funding negotiations with the government after her own colleagues wrote a letter accusing her of betrayal.

In a significant escalation in the internecine warfare that has rocked the crossbench party this year, leader Richard Di Natale and eight of his MPs have signed a letter of complaint against Senator Rhiannon over her actions during delicate discussions with the government this month.

The letter has been sent to the party's powerful national council as part of a bid to rein in the rogue senator and her hard left NSW faction as divisions once again spill over into the public eye.

Senator Rhiannon on Sunday said she had not broken faith with the party nor betrayed anyone's trust.