Border protection will be a key issue when voters in the South Australian federal seat of Mayo go to the polls, Liberal candidate Georgina Downer says.
Ms Downer campaigned on Tuesday with her father Alexander, who held the seat for 24 years, and Home Affairs Minister Peter Dutton.
"We cannot return to the bad old days, under Labor, where we saw 50,000 people seek to come to Australia by boat and 1200 people we know perish at sea," she told reporters at Mt Lofty.
"We cannot give an inch to the people smugglers."
Mr Dutton warned voters against supporting Centre Alliance candidate Rebekha Sharkie, who, he said, does not back the government's hardline stance.
"Rebekha Sharkie has sided with the Greens and with (Opposition Leader) Bill Shorten on every key decision to oppose us on our tough border protection policies," he said.
Ms Downer has previously criticised Ms Sharkie over her calls for an end to indefinite offshore detention and for asylum seekers to be resettled in New Zealand.
Mr Dutton is the latest in a string of high-profile Liberals to campaign alongside Ms Downer in the lead-up to Saturday's vote.
Prime Minister Malcolm Turnbull has visited twice, as well as former prime minister John Howard and senior Liberals Julie Bishop, Greg Hunt, Michaelia Cash, Simon Birmingham and Nationals Leader Michael McCormack.
Ms Sharkie said it was "terrific" that Liberal ministers had visited and that some had made funding commitments.
"I particularly like it when they bring a cheque book with them," she told AAP.
"Make no mistake, if I wasn't running they wouldn't be here and they wouldn't be making promises to our community."
She said she had asked Mr Turnbull to honour $20 million worth of promises made to the electorate during the 2016 election campaign, and he had agreed.
"Promises made to the electorate are there for the benefit of the electorate, they are not there to try and get a candidate a job," she said.
Ms Sharkie and Ms Downer have both said they will spend much of the final week of the campaign handing out how-to-vote cards at pre-poll booths in the electorate.
The pair stood with volunteers outside a Mount Barker booth on Tuesday morning, before Ms Sharkie came face-to-face with Mr Downer.
In an awkward moment, Mr Downer approached and greeted Ms Sharkie before joining his daughter in speaking with voters.
