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.