Nationals leader Barnaby Joyce could face a "liberal" candidate at the next election.
Mr Joyce is expected to face a tough contest against independent Tony Windsor in his NSW seat of New England.
But micro-parties and independents are also considering throwing their hats in the ring.
Liberal Democrats senator David Leyonhjelm said his party was weighing up whether to stand a candidate in New England.
"We will be the only party on the ballot paper with 'liberal' in our name," Senator Leyonhjelm told AAP on Thursday.
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"We expect to take votes off the National party."
Senator Leyonhjelm, who has worked closely with micro-parties in the past, said it had yet to be decided which of them would run in the seat.
"It is a very live topic," he said.
A recent Newspoll found Mr Windsor could win the seat on Labor, Greens and other preferences.
In 2013, Mr Joyce faced eight competitors in the wake of Mr Windsor retiring from parliament.
