Governor-General Sam Mostyn has revealed waking up to abusive messages with expletives and capital letters after she urged Australians to re-embrace “decency”.

Mostyn, a friend of Helen Haines, addressed the media after the Independent MP lost her second leg on Wednesday.

In strong comments on public discourse, Mostyn called on Australians to “relearn” how to be decent to one another and to “disagree well”.

But when she woke up on Thursday, her public plea had triggered more of the aggressive reactions she had been urging Australians against.

Mostyn told ABC News Breakfast that women in public roles were subjected to a “unique and pernicious form of attack”.

“I still receive that online. In fact I was just saddened this morning to see some of the comments on my own Instagram page that, in capitals, with expletives, once again questioning the very nature of what it is that I do,” she revealed.

“I think that women across the country know that there are certain things that are reserved for women in that attack that go to our gender and they are often vicious and just despicable.

“I know that is also what is being experienced by women, and men, across the country.”

Haines was struck by a four-wheel-drive vehicle outside her electorate office in Wangaratta, in northern Victoria, on Monday afternoon.

Police allege Brendan Nugent, 43, deliberately drove the LandCruiser into Haines, who lost both her legs to amputation after the incident.

On Monday, Mostyn posted on Instagram for people to reflect on the “growth of incivility” in the community, which was met with mostly positive comments.

On Wednesday, she said Australians were good people but needed to “relearn” how to treat each other better.

“Australians have good hearts, great hearts, and checking each of ourselves to ensure that we are, in fact, disagreeing well, not fighting with one another, not descending into violence and chaos and division,’’ Mostyn said.

“Most importantly, that we learn or relearn to exercise our muscle of decency.

“Australians are yearning for kindness and care. And they’re asking us why we’ve lost the great skill of disagreeing well and with decency to each other.

“Our democracy, the great Australian democracy, has ­always relied on passionate and robust debate.”

Mostyn said she had discussed the importance of civil debate and civic engagement with Haines during a meeting in her electorate earlier in October.

“And as we were leaving, because I’ve known Helen and I’ve admired her and her style, we started talking about this very issue,” she told News24.

“About what needs to be done, how would we have the conversation nationally about civility, respect for people who do stand for public office?

“I’d like to talk about encouraging more people to understand how our democracy works and to stop the deterioration of civics education.

“So we were having exactly that conversation, and we left with a hug, saying we must do more of this work because it’s so important to uplift the nation.”

The shocking attack has sparked debate about whether public officials are sufficiently protected from threats against their safety, including during the lead-up to the Victorian state election in November.

Premier Ben Carroll said additional security resources would be put in place for the November 28 poll.

“The (Victorian Electoral Commission), Victoria Police and all political parties take the safety of this election very seriously,” he told reporters on Wednesday.

“What has happened must be a turning point for political debate in Victoria and around Australia.”

The state Labor leader did not say where those extra resources would be directed, but insisted authorities were collaborating closely.

He said the level of co-operation between Victoria Police and the electoral commission was “unprecedented”.