[1][2][3][4] Amid the 2017–18 Australian parliamentary eligibility crisis, the trigger for the by-election was the resignation of Liberal incumbent John Alexander effective 11 November 2017.

[5] Speaker of the House of Representatives Tony Smith issued the writ for the election on 13 November 2017, the same day that Alexander submitted his resignation.

Following the win by Barnaby Joyce in a similarly Section 44 triggered by-election in the Division of New England on 2 December 2017, the Liberal-National coalition maintained its one-seat majority in the Australian House of Representatives.

Given this unusual opportunity for an Opposition to destabilise the government's position in parliament outside of a general election, the Labor Party chose former New South Wales Premier Kristina Keneally as a high-profile candidate.

[26] On 14 December 2017, it was revealed that Liberal candidate John Alexander had failed the requirement to declare rental income to the parliamentary register of members' interests from his $1440-a-day 100-acre $4.8-million property in the New South Wales Southern Highlands which he had purchased in June 2017.