The Centre Alliance's Rebekha Sharkie is one of four MPs who have been forced to resign from Parliament because the renunciation of their British citizenship had not been finalised by the close of nominations for the 2016 Federal election.

Margin

Rebekha Sharkie holds Mayo for the Central Alliance with a margin of 5.0% versus the Liberal Party.

Date

Saturday 28 July. More information on the by-election, including where to pre-poll vote or vote on polling day, can be found at the Australian Electoral Commission's website.

MP

Rebekha Sharkie since the 2016 election. Elected for the Nick Xenophon Team, the party has adopted the new name Centre Alliance following the departure of Nick Xenophon from the Senate.

Profile

Mayo is based in the Adelaide Hills and also includes the Fleurieu Peninsula and Kangaroo Island to the south of Adelaide. The main population centres include Bridgewater, Mount Barker, Victor Harbor and Goolwa. The electorate covers 9,315 sq.km. (AEC Map)

A redistribution of electoral boundaries is underway in South Australia, but the by-election will be conducted on the old boundaries. The new electoral boundaries will not apply until the Federal election.

History Mayo was created in 1984 and named after Helen Mayo, founder of the Mothers and Babies Association and the first woman elected to an Australian University Council.



Mayo was held for the Liberal Party by Alexander Downer from its first contest in 1984 until his retirement in 2008. Downer succeeded Dr John Hewson as Liberal Leader in May 1994 and resigned in favour of John Howard in January 1995. Downer served as Foreign Minister through the entire eleven and a half years of the Howard government. He was appointed Australian High Commissioner in London by the Abbott government, leaving the post in early 2018. Alexander Downer's grandfather Sir John Downer served two periods as South Australian Premier between 1885 and 1893, participated in the Constitutional Conventions that debated the Australian Constitution, and served in the first Senate between 1901 and 1903. Alexander's father Sir Alick Downer served in the House of Representatives 1949-64, was Minister for Immigration 1958-63 and served as Australian High Commissioner in London 1964-72 while Alexander Downer was in his teens.



Mayo had been held by the Liberal Party until lost to Rebekha Sharkie at the 2016 election. The seat is a safe non-Labor seat, but that isn't the same as being a safe Liberal seat. The Liberal loss in 2016 was not overly surprising given two early close contests.



The first was in 1998 when former Redgum lead singer and Australian Democrat candidate John Schumann finished second and came close to victory thanks to Labor and One Nation preferences. The second scare was at the 2008 Mayo by-election following Alexander Downer's retirement. The by-election took place at a time when the state of the Murray River was a significant local issue in South Australia. With no Labor Party candidate contesting, the Greens ran the Liberal Party a surprisingly tight race, successful Liberal candidate Jamie Briggs having his margin cut to 3.0%.



Briggs was easily re-elected at more conventional two-party contests against Labor in 2010 and 2013. He served in the outer ministry in the Abbott and Turnbull governments, but was forced to resign at the end of 2015 following an incident involving a DFAT staff member in a Hong Kong bar. The Nick Xenophon Team contested all South Australian lower house seat at the 2016 election, with Mayo clearly the party's best chance of victory. The presence of Jamie Briggs as the Liberal candidate made the seat an even greater target. The Xenophon Team's Rebekha Sharkie had previously worked for Briggs and the Liberal Party as an adviser. She polled 34.9% to 37.8% for Briggs at the 2016 election, easily closing the gap after receiving more than 80% of Labor and Green preferences.



Sharkie had residual British citizenship which she moved to renounce well ahead of the election. However, delays in paperwork processing by the British bureaucracy meant that Sharkie's citizenship had not been formally renounced before the close of nominations. Following the High Court's decision on a similar case concerning Labor's Senator Katy Gallagher, Sharkie resigned from Parliament, triggering the by-election. Past Election Results Year Winning Party 1984 LIB 1987 LIB 1990 LIB 1993 LIB 1996 LIB 1998 LIB 2001 LIB 2004 LIB 2007 LIB 2008By LIB 2010 LIB 2013 LIB 2016 NXT Coloured tab indicates seat won by a party forming government As the graph of two-party preferred results below shows, Mayo has always seen the Liberal Party poll 5-10% above the Liberal two-party result for South Australia as a whole. However, the three gold points on the graph show the seat was much more marginal at elections when a minor party or independent finished second, the Australian Demmocrats in 1998, the Greens at the 2008 by-election, and Rebekha Sharkie for the Nick Xenophon Team at the 2016 Federal election. Mayo - Result After Preferences - 1983-2016 As the graph of first preference results below shows, when the Liberal Party's main opponent was Labor, the Liberal first preference vote was above 50%. When a credible third party candidate entered the fray, or Labor was absent as at the 2008 by-election, the Liberal vote fell below 50%, putting the seat at risk from strong flows of preferences between third party candidates. In 1998 and 2008, the Liberal Party retained Mayo thanks to its first preference support staying above 40%. When it fell below this level to 37.8% in 2016, the Liberal Party could not hold the seat against a strong third party challenger such as Rebekha Sharkie. Mayo - First Preference Votes by Party - 1984-2016 In 1998 the Democrats received 80.9% of all third party preferences. Preference flows have not been as strong since, favouring the Greens 68.5% at the 2008 by-election, and favouring Rebekha Sharkie 73.4% in 2016. In 2016 Labor preferences were 80% to Sharkie, Green preferences 86%, while Liberal Democrat preferences flowed 55% to the Liberal Party and Family First 59%.

Polling Place Results 2016

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Enrolment There are 107,672 electors enrolled for the by-election., up 3,691 or 3.5% in the two years since the 2016 election. Opinion Polls ReachTEL and YouGov Galaxy polls released in early June reported that Rebekha Sharkie was well ahead of Liberal Georgina Downer. Both polls reported Sharkie ahead 58% to 42% after preferences. Another ReachTEL poll commissioned by the Australia Institute and published on 24 June had Sharkie even further ahead 62% to 38% from first preferences of Sharkie 43.5%, Downer 32.7%, Labor 8.2%, Greens 9.0%, Other/Independent 4.1% and Undecided 2.6%. A YouGov/Galaxy poll reported in News Limited local papers on 23 July had Rebekha Sharkie leading on first preferences 47% to 35% for Georgina Downer, Labor 9% and the Greens 7%. After preferences the poll predicted Sharkie to win 59% to 41%.

2016 Mayo Result