An internal memo circulated to local branch members this week revealed December 21 as D-day ahead of the upcoming 2015 state election.

But, the stoush between the city's deputy mayor Andrew Negline and incumbent MP Daryl Maguire for preselection is just part of the process.

That's according to the man who has been there plenty of times himself former Liberal party MP, Alby Schultz.

"Preselections, in many instances, are controversial, but they are a very necessary part of the democratic process which occurs in the Liberal Party," Mr Schultz said.

"Some sitting members think they own the preselection process ... but they don't."

Mr Schultz said the process allowed rank and file members who have chosen to be preselectors the chance to vote on who they want to represent them as a candidate.

He said he was never fazed when someone challenged him and believed a sitting member shouldn't get upset, just "accept it as part of the process".

"(They need to) get on with the job of convincing the preselectors they've worked hard as their representative," Mr Schultz said.

The candidate will be determined by 33 preselectors from the three Liberal Party branches within the Wagga electorate, alongside input from the party's state headquarters.

Both Wagga branches will vote tomorrow to elect preselectors, with Tumut to follow on Sunday.

Mr Maguire and Mr Negline are still unable to comment on the preselection.

Under the party's constitution, candidates are forbidden from commenting without the authorisation of the party's state director.