Senator Mehreen Faruqi is suing the One Nation leader in the Federal Court over alleged racist discrimination through a September 2022 tweet.

At the time, Senator Hanson wrote that she was appalled and disgusted with Senator Faruqi’s comments, telling her to “pack (her) bags and piss off back to Pakistan”.

She had responded to an earlier tweet by Senator Faruqi who wrote she could not mourn the passing of the leader of a “racist empire built on stolen lives, land and wealth of colonised peoples”.

As the trial began on Monday, Senator Faruqi’s barrister Saul Holt KC said the tweet was targeted towards his client as a Muslim woman of colour who had migrated to Australia.

The “demeaning and insulting” language caused people like Senator Faruqi and others to feel a range of psychological effects including fear, anxiety and stress, Mr Holt said.

The tweet had to be understood in the wider context of racism which was “pernicious and deeply harmful” as well as the One Nation leader’s tendency to say racist things, he told Justice Angus Stewart.

In an affidavit, Senator Faruqi says she felt like she was not accepted in Australia and became fearful of the hate and racism that Senator Hanson’s tweet would encourage.

“A tweet of this kind in the Twittersphere, the dogwhistle doesn’t just stand on its own,” Mr Holt said.Under cross-examination, Senator Faruqi was taken to a December 2017 tweet by her son Osman.

“Mediocre white people. They should be in the bin but instead they own everything but are every f***ing where,” he wrote.

She denied the post was racist.

“Racism when it’s about people’s ethnicity and skin colour is also about who holds power in this country,” she told the court.

Senator Hanson’s barrister Sue Chrysanthou SC suggested the Greens deputy leader, despite saying she was against all racism, found some forms “acceptable”.

Senator Faruqi is seeking court orders the One Nation leader donate $150,000 to a charity of the Greens senator’s choice.

In her openings, Ms Chrysanthou called the lawsuit “unmeritorious”, arguing her client had responded to an offensive tweet by the Greens senator which was designed to provoke a response.

Senator Faruqi was a hypocrite posting about the Queen in this way as she had previously sworn an oath to the former monarch when she became an Australian senator, the court heard,

For five hours after the Greens senator had posted the tweet, she experienced a barrage of racist comments before Senator Hanson even responded, Ms Chrysanthou argued.

The One Nation leader’s eventual tweet did not target one particular race, colour or ethnic origin, the court heard.

“The wording used by my client … is directed to Senator Faruqi and Senator Faruqi alone,” Ms Chrysanthou said.

The tweet was a fair comment based on Senator Hanson’s honest opinion and did not fall foul of the Racial Discrimination Act, the court was told.

Ms Chrysanthou argued the specific provisions in the act relied on by Senator Faruqi should be struck out as they came up against the implied constitutional right of political communication.

“These provisions impose a substantial and significant burden on political communication in this country in circumstances where immigration is plainly a political issue of concern to many Australians,” she said.

Representing the Commonwealth Attorney-General, Craig Lenehan SC rejected these arguments, saying any burden was “very small”.

The trial continues.