McWilliams was replaced as leader in 1921 and defeated in the 1922 election but the Country Party gained Darwin with Joshua Whitsitt.

At the 1922 state election Whitsitt stood down to transfer to federal politics and Dixon was defeated but Blyth led the party to gain three further members Richard Franks (Darwin, holding Whitsitt's seat), John Piggott (Franklin, taking Dixon's seat) and Albert Bendall (Wilmot).

The overall result gave the Country Party the balance of power and they were able to force the replacement of Premier Walter Lee with John Hayes at the head of a coalition with Blyth as minister for lands and mines.

[7] However the party was to soon fall apart during the Assembly's term, with Piggott sitting as an Independent, Blyth and Bendall moving to the Nationalists and Hobbs joining a "Liberal" grouping based on Lee.

[9] For the next few decades there was virtually no Country Party electoral activity in the state bar a single candidacy in Franklin in the 1934 federal election.

[19] The party reorganised and registered in the state in 2013[20] and were subsequently joined by former Labor minister Allison Ritchie.

[25] In May 2018 Steve Martin, a Senator originally elected for the Jacqui Lambie Network who had subsequently been expelled, joined the Nationals, giving them their first federal representative in the state in ninety years.

At the conference, Steve Martin announced that he would stand for re-election at the 2019 federal election and stated that the party hoped to field additional candidates.

[29] Steve Martin failed in his bid to win election to the Senate, polling just over one percent of the statewide vote.