Thousands of South Australian voters have already cast their vote ahead of the May 18 Election

Thousands of South Australians have already cast their vote ahead of the May 18 Federal Election.

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Thousands of South Australians have already cast their vote ahead of the May 18 Federal Election.

Early voting centres opened around Australia last week and 660,000 ballot papers have already been cast nationwide.

More than 6000 people in the Adelaide Hills and Fleurieu seat of Mayo voted in the first week – a 337 per cent increase from the 1371 votes recorded during the first four days of pre-polling at the 2016 election.

Australian Electoral Commission data also reveals that the second-highest pre-polls have been for the seat of Boothby – the state’s most marginal at 2.8 per cent – with 4141 votes cast so far.

Almost 3 per cent of South Australians registered to vote, or 32,219, did so at centres last week, as more centres open across the state on Monday.

Flinders University political analyst Dr Rob Manwaring says early voting is a growing trend.

“For some voters that’s a choice that they have already made up their mind, and therefore they can switch off from the rest of the campaign,” Dr Manwaring said.

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He said a high level of engagement in Mayo and Boothby was not surprising because they were two critical seats. “It’s very unusual for a minor party candidate (Rebekha Sharkie) holding a seat in the Lower House,” he said.

“(Liberal candidate) Georgina Downer is a very polarising candidate, a very high-profile one, so again it means that people are switched on to it.”

Boothby, held on a knife-edge by Liberal MP Nicolle Flint, is the seat “that the Liberals and Government is most likely to lose”, Dr Manwaring said.

Boothby MP Nicolle Flint said the high turnout at early voting stations highlights how engaged voters are with the important choice at this election “between our Government’s strong economic record and the risks of a Shorten Labor government”.

Dr Manwaring expects both major parties will use the next week of the campaign to target swinging voters, with last minute financial announcements being made to sandbag support in critical seats.

Centre Alliance MP Rebekha Sharkie, who says she nearly ran out of how-to-vote cards on the first day of pre-polling at Victor Harbor, wants early voting restricted to just two weeks before election day.

“Three weeks is a long time, especially for the volunteers who hand out the how to vote cards,” Ms Sharkie said.