McVeigh's appointment as Queensland Agent-General in London led to his resignation, with both the National and Liberal parties contesting the ensuing by-election.

The outgoing MP, John McVeigh, was elected to federal parliament in 2016, having previously served in the Legislative Assembly of Queensland as the member for Toowoomba South.

McVeigh's pre-selection triggered the 2016 Toowoomba South state by-election, with the seat being retained by the Liberal Nationals.

[8] Preselection for the Liberal National Party was to be held on 25 October, and was expected to be contested by eight candidates:[9] Prior to the preselection, van Gend's candidacy was endorsed by several prominent conservatives, including Canavan, Tasmanian senator Eric Abetz, former Nationals leader and Deputy Prime Minister John Anderson and columnist Miranda Devine.

[10] Councillor Vonhoff was believed to have to the backing of Prime Minister Scott Morrison and former Groom MP Ian Macfarlane.