Former federal Greens leader Bob Brown held talks with a group of NSW Greens MPs about forming a new breakaway party as the civil war inside the state branch reached boiling point.

The discussions, which were continuing among the MPs as late as last December, advanced to the point that designs for a party logo and website, as well as party branding as "Green independents", had been canvassed, sources told the Herald.

Former Greens leader Bob Brown considered talks on forming a breakaway Greens party but ultimately decided they should stay united. Credit:Karleen Minney

Upper house MPs Cate Faehrmann, Justin Field, Jeremy Buckingham and Dawn Walker met Mr Brown in August to discuss the prospect of forming a new environmental party amid a deepening ideological rift within the NSW Greens.

Mr Brown confirmed that the option of a split was discussed at the meeting, describing them as "general discussions", and said he had counselled the group to instead push for reform inside the party.