A former federal political staffer colleague of Bruce Lehrmann tendered her resignation after a "heated" argument with the man, a court has heard. Former media advisor to Senator Linda Reynolds, Nicole Hamer, said she felt "ganged up" on by Mr Lehrmann in March 2019 after defending Brittany Higgins at a Canberra pub. The man's Federal Court civil proceedings against Network Ten and Lisa Wilkinson entered their 10th day on Wednesday. The former Liberal staffer turned law student is suing the parties for defamation over a 2021 The Project story, which aired Brittany Higgins' allegation she was raped in Parliament House two years earlier. Ms Hamer was the first witness to sit in the Federal Court witness box on Wednesday morning as part of Ten and Ms Wilkinson's defence. The court previously heard Ms Hamer, Mr Lehrmann, Ms Higgins and fellow staffer Jesse Wotton drank together at The Kingston Hotel on March 2, 2019, weeks prior to the alleged rape. According to Ms Hamer, Mr Lehrmann asked her to reach out to Ms Higgins and invite her to the Saturday afternoon drinks. "He made a comment saying 'Brittany is good looking, can you reach out to her on Instagram and see [if] she's free to come to the pub'," Ms Hamer said. Mr Lehrmann has denied ever doing this. And as Ms Higgins had asserted during her evidence, Ms Hamer said Ms Higgins had been prevented from leaving the pub for a short time after the two women had discussed the possibility of working together. "Brittany picked up her phone to book an Uber and Bruce took her phone away as a bit of play. I guess to stop her from being able to book her Uber," Ms Hamer told the court. "He said, 'Just stay for one more drink'." Mr Lehrmann has also denied this claim. Ms Hamer said the phone was returned after a short time but that she got into an argument with Mr Lehrmann after Ms Higgins left the pub. "Bruce said that I'd overreacted in the way I'd spoken up and tried to defend Brittany, so I got quite defensive to that," Ms Hamer said. The court heard Ms Hamer sent a letter of resignation to her minister boss that evening after the argument had been the last straw in a job she was growing to dislike. MORE TRIAL COVERAGE: She said Mr Lehrmann told her she "acted like a feminist" who always defended women. "[The argument] was one of the reasons [for quitting]. I'd been unhappy in the office and I felt like I was being ganged up on by Bruce," Ms Hamer said. Mr Lehrmann's barrister Steven Whybrow SC, who said the argument was actually with Mr Wotton, responded: "A gang of one?" "I just felt uncomfortable," Ms Hamer, who withdrew her resignation after speaking with the senator, replied. Mr Lehrmann and Ms Higgins each previously spent multiple days in the witness box to vehemently and repeatedly defend their accounts of what happened in the early hours of March 23, 2019. On Wednesday, Ten began calling its 20 other supporting witnesses, which will include former federal government staffers, security guards, police officers and expert witnesses. The media company and high profile journalist are attempting to prove the rape allegation is substantially true and that reporting it professionally was justified in the public interest. Mr Lehrmann has always denied raping Ms Higgins in 2019 in the office of the then-defence industry minister and no findings have been made against him. His criminal trial was aborted last year due to juror misconduct and the charge levelled at him was later dropped. The trial continues.