The National Party will officially open nominations to re-select a candidate for the Clutha-Southland electorate this week.
Its current MP, Todd Barclay, announced last week he would not stand at this year's general election.
Police have reopened an investigation into a secret recording Mr Barclay is alleged to have made of a former electorate staff member in the Gore office.
The controversy ended Mr Barclay's political career.
National Party southern region chairperson Rachel Bird has confirmed nominations for the seat open at midday tomorrow and close on 18 July.
Ms Bird said nominees would go through several meet-the-candidates meetings before a final selection was made in August.