Greens senator Mehreen Faruqi has told the federal court that verbal attacks on white people in Australia are not racist because racism is “tied to power” and in this country, “the power.. is held by white people”.

Faruqi is suing One Nation senator Pauline Hanson in the federal court over what Faruqi has called “the ultimate racist slur” – a social media post that told her to “pack your bags and piss off back to Pakistan”.

Through her lawyer, Sue Chrysanthou SC, Hanson has accused Faruqi of hypocrisy and political grandstanding in pursuing the legal action while excusing what she acknowledges were racist remarks inside her own party. Hanson accused Faruqi of making or endorsing comments condemning white people.

Faruqi was the first witness on Monday in a case that could test the constitutional validity of section 18C of the Racial Discrimination Act, which Chrysanthou argued potentially undermined the constitutionally implied right to political communication. The case is also examining what constitutes racism and whether power imbalances play a role in defining it.

Faruqi has accused Hanson of breaching section 18C, which prohibits an act that is reasonably likely to offend, insult, humiliate or intimidate a person or group because of their race, colour, nationality or ethnicity.

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Her complaint is based on a post Hanson made on the social media platform Twitter, now called X, in September 2022.

“I understood her words, to be the ultimate racist slur,” Faruqi said under cross-examination from Hanson’s lawyer, Sue Chrysanthou SC. “Implying and clearly saying that I don’t belong here. So it really challenged my sense of belonging to this country.”

Chrysanthou accused the Pakistani-born senator, who migrated to Australia in 1992 and later became an Australian citizen, of targeting Hanson because she was a political opponent.

“You’ve come here to use the witness box as a soapbox to give speeches to further your political ends,” Chrysanthou put to Faruqi. The Greens senator said she had not.

“I understood this to be particularly pointed at me, that I don’t have the same rights to have the same benefits that Australia offered every other citizen of this country,” Faruqi said.

Chrysanthou suggested that Faruqi was a “hypocrite” who had made and endorsed racist remarks about white people.

Justice Angus Stewart challenged whether such comments about white people were automatically racist. He pointed to differing views on the allegedly abusive comments about whiteness made by Samantha Kerr, captain of Australia’s Matildas football team, to a London taxi driver, as evidence there was public debate.

The Greens senator insisted remarks that her journalist son Osman Faruqi had made on social media criticising white people were not racist because racism was also about power.

“It is tied to who holds the power and who has the authority to perpetrate racism and oppress people,” Faruqi said. “And in this country, the power of that is held by white people.”

The federal court case centres on a Twitter exchange between the two senators on 9 September 2022, shortly after Queen Elizabeth II died. After news of the monarch’s death had emerged overnight, Faruqi posted a message on Twitter at about 11.15am.

“Condolences to those who mourn the Queen,” the post said. “I cannot mourn the leader of a racist empire built on stolen lives, land and wealth of colonised peoples. We are reminded of the urgency of Treaty with First Nations, justice & reparations for British colonies & becoming a republic.”

Just under five hours later, Hanson quoted Faruqi’s tweet and posted a response.

“Your attitude appalls and disgusts me,” Hanson’s post said. “When you immigrated to Australia you took every advantage of this country. You took citizenship, bought multiple homes, and a job in a parliament. It’s clear you’re not happy, so pack your bags and piss off back to Pakistan.”

Chrysanthou told the court Faruqi had posted her original tweet on a day and at a time designed to provoke a response. Long before Hanson posted her response, she said Faruqi had already received a barrage of similarly critical responses.

Faruqi’s lawyer, Saul Holt KC, suggested the words in Hanson’s tweet were more likely to offend and humiliate because of who said them.

“They were spoken by Pauline Hanson, a senator of the Australian Parliament, the leader of a political party and so to use the modern term ‘an influencer’ - a well known long standing and prolific sire of racist things, particularly anti migrant and anti Muslim things,” Holt said.

Chrysanthou suggested Hanson’s tweet was only accusing Faruqi of hypocrisy.

“Senator Hanson was targeting me with racism,” Faruqi replied. Earlier, Holt told the court that Hanson’s wording was “just a version of the well-known anti-migrant, racist, nativist phrase ‘go back to where you came from’”.

Faruqi defended her original tweet, saying every MP or senator had the right to criticise Australia’s institutions.

“That’s how change happens for the better. And that was my reason for doing this. That’s not hypocrisy.”

Faruqi is asking the court to make Hanson delete the post, undertake anti-racism training at her own expense and donate $150,000 to a charity of Faruqi’s choosing.

Hanson’s lawyers argue her tweet falls within the Racial Discrimination Act’s exemptions because she acted reasonably and her comments were made in good faith and reflected a genuine belief.

Hanson is due to give evidence on Tuesday.

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