Four people have put their hand up to represent the Nationals in the Eden-Monaro by-election, with the party to conduct its pre-selection process just days before rolls close for nominees.

Yass businesswoman and former ACT public servant Fleur Flanery, Queanbeyan councillor Trevor Hicks, Cooma grazier Michael Green and Bywong nutritionist Mareeta Grundy will be seeking the votes of around 200 local members on Saturday.

The two men and two women will be hoping to turn the by-election into a three-cornered contest, with the Liberals to be represented by Fiona Kotvojs and Kristy McBain for Labor.

A crowded field is set to contest the election, with a dozen people set to be on the ballot paper on July 4.

The road to the by-election hasn't been smooth for the party, with NSW Nationals leader John Barilaro widely tipped to run before he withdrew from the race, amid speculation he didn't have the support of federal Nationals leader Michael McCormack.

In leaked text messages between the pair, Mr Barilaro reportedly said Mr McCormack felt threatened by his bid.

After Mr Barilaro bowed out it was unclear if the Nationals would contest the seat, but the local membership pushed for the party to run.

Despite Eden-Monaro's regional location, the Nationals have never held the seat, which has swung between the Labor and Liberal parties and was considered a bellwether seat until 2016.

The by-election was triggered by the resignation of Labor MP Mike Kelly due to health issues.

Nominations for candidates for the by-election close on Tuesday.