Baroness Uddin was grilled on cheating her expenses in a dramatic final afternoon of the High Court challenge against Tower Hamlets mayor Lutfur Rahman's election victory.
The Labour peer was appearing as a witness for Mr Rahman's team at the Royal Courts of Justice on Friday.
In the hearing she criticised the mayor's rival in last year's vote, John Biggs - who she served under when he was leader of Tower Hamlets in 1990 - for "provocative comments" and not being a "team player".
However, the former deputy leader of Tower Hamlets Council was also forced to face a number of questions from barrister for the election petition - four voters who have brought the case against the mayor - on her previous conduct that saw her suspended from the House of Lords over £124,000 in unpaid expenses.
Francis Hoar probed the baroness over a house in Maidstone which was the focus of a 2009 Sunday Times investigation. The investigation culminated in a Privileges and Conduct Committee ordering her to pay back the money.
Baroness Uddin declined to answer questions over the scandal before commissioner Richard Mawrey QC, acting as a judge, ordered her to do so.
It led to Mr Hoar to remark: "You're doing everything in your power to obfuscate."
She responded: "I've never lied about my circumstances and my past and I'm here to give answers to the best of my ability."
Baroness Uddin, who returned to the House of Lords in 2012, revealed she had been given more time to pay back the money.
She was also questioned on another Sunday Times story which said she exchanged a Honda valued at around £300 for a two-year-old BMW worth over £20,000 without paying any money.
The incident happened at a garage then-owned by Mohammed Ferdhaus who also owns Bangladeshi television station Channel S, which broadcasts in Britain.
Mr Hoar said: "This gift of around £15,000 from the owner of Channel S was not declared to the House of Lords."
Baroness Uddin responded: "I didn't receive a gift from anyone in the way of a car, otherwise I would have gone to the House of Lords to register that."
She also denied her Honda was of low value. "It wasn't a tattered car. I've never driven a tattered car."
She was said to have paid the money at a later date.
In the claims against Mr Biggs, the baroness said, regarding his leadership, there were concerns he was working too closely with council officers from the previous Liberal Democrat regime.
She went on to accuse Mr Biggs of saying to her Tower Hamlets was "not ready" for a female Bangladeshi leader. Mr Biggs denies this.
She also commented on a Sunday Politics interview gave before the election regarding a quote he gave about the mayor's cabinet favouring the Bangladeshi community.
The interview led to accusations of racism being levelled at Mr Biggs, which remains a key allegation against Mr Rahman.
Baroness Uddin said: "It was unwise and unfitting of someone wanting to represent the whole borough."
Mayor Rahman denies all the allegations, which also include voter fraud.
The court will return on March 23 for closing statements, while a ruling is expected after Easter. If the judge finds against Mr Rahman, he may lose his position as mayor.
The case continues.