Former independent MP Tony Windsor will declare on Thursday whether he will take on Barnaby Joyce at the next election.
Mr Windsor, who has scheduled a media conference in Canberra for 10am AEDT on Thursday, declined to say on Wednesday what he had in mind.
Mr Joyce, the deputy prime minister and Nationals leader, holds Mr Windsor's former seat of New England by a margin of around 20 per cent.
A petition on the GetUp website has so far attracted 3900 signatures supporting Mr Windsor's return to parliament.
Liverpool Plains farmer Rosemary Nankivell, who set up the petition, said the rich agricultural area was being put at risk by coal and gas development.
She said Mr Joyce had been "silent" on the issue and the area needed someone who would stand up for farmers.
Mr Windsor retired at the 2013 election after 12 years in parliament, having been a key figure in keeping the Gillard minority government in power.
His agreement with the then Labor prime minister Julia Gillard reaped many benefits for the rural NSW seat, from the national broadband network to hospital funding.
Mr Joyce made political history in 2013 in his shift from being a Queensland senator to a NSW lower house member.
He grew up in the New England area, went to university there and started work as an accountant before moving to southwest Queensland.
Mr Windsor's hopes of winning back the seat will rely heavily on preferences from Labor, the Greens and other independents.
A key issue will be the proposed Shenhua Watermark coalmine, which has conditional government approval, but still needs a NSW mining licence and federal approval for the project's water management plan before it can go ahead.
Farmers fear it will irreparably damage groundwater that feeds the fertile farmlands.
