along with seats in all states and territories at the 2016 election, with Xenophon citing the government's ambiguity on the Collins-class submarine replacement project as motivation. ABC psephologist Antony Green's 2016 federal election guide for South Australia stated NXT had a "strong chance of winning lower house seats and three or four Senate seats". NXT's candidate in Mayo was former Briggs staffer Rebekha Sharkie, who is associated with a wide range of organisations in the Adelaide Hills. Multiple seat-level opinion polls in Mayo found NXT surprisingly leading the Liberals on the two-candidate vote during the 2016 election campaign. Seat-level opinion polls in the other two rural Liberal South Australian seats, both Grey and Barker, also found NXT leading the Liberals. Sharkie was successful in defeating Liberal incumbent Briggs in Mayo at the 2016 election with a 55 percent two-candidate vote to the Liberals' 45 percent two-candidate vote. Briggs lost over 16 percent of his primary vote from 2013, and ultimately suffered a two-candidate swing of 17.2 percent. This marked the first time this seat has been out of Liberal hands since its creation. Additionally, Mayo became a marginal seat in a "traditional" two-party matchup for the first time, with the Liberal two-party-preferred vote reduced to 55.4 percent, a swing of 7.2 percent. Sharkie resigned on 9 May 2018, as a result of the ongoing Australian parliamentary eligibility crisis following the ruling of the High Court that dual British citizens must have completed renunciation of their British citizenship prior to nominating for Australian Parliament with reference to Katy Gallagher. The resignation triggered a by-election, held on 28 July 2018. Sharkie re-contested the seat for her party, now known as the Centre Alliance, and retained it with a modest swing in her favour. Sharkie retained the seat at the 2019 election with an increased majority despite a collapse in voteshare for the Centre Alliance that year. Sharkie retained her seat in the 2022 election with an increased majority and a swing of 7.12 percent to her. Members Election results See also 2016 Australian federal election Results of the Australian federal election, 2016 (South Australia) References ABC profile for Mayo: 2016 Poll Bludger profile for Mayo: 2016 AEC profile for Mayo: 2016 Notes External links SA boundary map, 2001: AEC SA boundary map, 1984: Atlas SA Electoral divisions of Australia Constituencies established in 1984 1984 establishments in Australia Kangaroo Island