Federal Greens MPs have launched an extraordinary attack on their colleague Lee Rhiannon, accusing the senator of betraying them by attempting to derail the party's school funding negotiations with the Turnbull government.

Fairfax Media can reveal all nine of Senator Rhiannon's federal colleagues – including leader Richard Di Natale – have co-signed a letter of complaint against her that has been sent to the powerful Greens national council.

A senior Greens source described the intervention as "seismic" and said it could make the NSW hardliner's position in Parliament untenable.

Another source said: "This is unprecedented. Lee has breached the faith of the party and the party room."