South Australian Liberal candidate Georgina Downer — who is vying for the seat of Mayo in the upcoming by-election — has deleted her Twitter account, blaming "trolls" using "unacceptable language".

The daughter of one-time Liberal leader Alexander Downer started her campaign about six weeks ago, after being endorsed by the party in mid-May.

Alexander Downer held the seat for 24 years until his retirement in 2008.

Georgina Downer said she made the decision to delete her Twitter account after some users started directing "insults" and bad language at her.

"I am no longer active on Twitter because quite frankly Twitter is not the best place where we as political candidates find it's best to engage with our communities," she said.

"I use Facebook as my medium for engagement with people in Mayo.

"Where there are comments that are unacceptable or trolls… then we don't think they are fruitful for political debates and commentary."

Prime Minister Malcolm Turnbull has helped Georgina Downer's campaign in South Australia. ( Facebook: Georgina Downer )

Not trying to stop debate: Downer

Ms Downer denied she was trying to shut down debate, in the lead up to the July 28 by-election.

"I would not seek to shut down those debates in the public sphere," she said.

"On my Facebook page, we have protocols in place that encourage polite debate and frank debate.

"Where those limits are exceeded and language that is unacceptable… and goes to insults… there's no place for it on our particular Facebook page."

However, multiple Twitter users have openly complained that when they have commented or asked questions on Georgina Downer's social media accounts, they had their feedback deleted and were blocked from commenting further.

Professor Tim Stephens wrote: "My question to Ms Downer on FB re climate change lasted five minutes before being deleted. Odd and undemocratic behaviour for a candidate seeking election to the Australian Parliament."

Loading

Another Twitter user Ryan Hopprich wrote: "Add me to the list of people that politely asked her about her thoughts on climate change and was blocked."

Downer still confident of her chances at the polls

Centre Alliance candidate and former Lower House MP Rebekha Sharkie has been polling strongly in Mayo, but Ms Downer said she was feeling confident about her chances.

"I've been really enjoying campaigning in Mayo in the Adelaide Hills and the Fleurieu and I'm looking forward to Kangaroo Island next week," she said.

"I'm very comfortable with how the campaign is going.

"I'm looking forward to the next six or so weeks, getting out there and making sure I'm listening."

Ms Sharkie won the seat of Mayo in the 2016 federal election as part of the Nick Xenophon Team, but resigned in May over her dual-citizenship, sparking the by-election.