Aspiring musician: Sally Street. Credit:Ben Rushton/Getty Images Mr Street admits he borrowed money in 2006 when he was struggling to pay the mortgage on a six-bedroom Vaucluse mansion but says the loans were given on an interest-free basis. Further, he says Ms Street, who he married in 2000 and separated from in September 2013, should be liable for half the debt. But Ms McDonald has accused her former son-in-law of using his legal prowess to take advantage of her and is seeking a total of $836,989.39 to cover interest accrued on the loan, plus damages and costs. She also wants Mr Street to have no recourse against her daughter, arguing they all agreed he was solely responsible for repaying the loans because Ms Street gave up her career as a mergers and acquisitions lawyer when she fell pregnant with their daughter around the same time as the loan was made.

The court heard Ms Street, who is pursing a career as an independent singer-songwriter and "diamond-encrusted keytar player", is virtually broke and is supplementing her $600-a-fortnight Centrelink payment with monthly live music performances, which earn her about $200. Ms Street said she recently hocked a $10,000 ring for $2000 so she could afford to buy food. Last week Associate Justice Joanne Harrison ordered Mr Street to pay Ms Street $8600 to go towards rent on her $1150-a-week two-bedroom apartment in Watsons Bay and the $2000-a-month hire purchase payments on her Porsche. He also has to pay $1300 a month in child support. Justice Harrison agreed to Mr Street's request to vary the garnishee order on the condition 50 per cent of his income is put towards his $230,000 Tax Office debt and the remainder, after payments to Ms Street, is split equally between Ms McDonald and himself. The judge said she wanted to strike a balance so all parties could afford to survive financially until the proceedings resolved, and if Mr Street couldn't pay his creditors, it would be financially disastrous for all concerned.

"If this situation becomes a reality then it is likely that Sandy Street would not be able to pay Helen McDonald's judgment debt as he may face bankruptcy. It is likely that none of the parties would be able to meet their day-to-day costs of living," Justice Harrison said, adding Mr Street's financial woes were not because he was living a lavish lifestyle. Mr Street was also successful in having the case transferred to the Family Court, where he initiated proceedings on July 14 seeking the debt be declared a joint matrimonial liability, meaning Ms Street is responsible for half. He says unless the orders are made under family law, Ms McDonald will never force her daughter to make any contribution to the debt. Against Ms McDonald's strong objection, Justice Harrison agreed to cross-vest the proceedings to avoid duplication and save costs. Ms McDonald is a pensioner with no assets and the money owed to her is her only savings, she says. Mr Street has recently spent $4400 on one of his adult son's engagement parties and $25,000 on a second-hand Lexus four-wheel-drive. Since the July garnishee order, he has paid her $20,500 towards the judgment debt as well as her rent, electricity and phone bill. Mr Street says he owes money to the Tax Office, his super fund and numerous credit providers. He has no savings, shares or property and is living with his mother. He earned almost $775,000 gross income in the 2013 financial year.

The silk is part of a formidable legal dynasty as his father, Sir Laurence, grandfather and great-grandfather were all chief justices of NSW. He made a name for himself in 2009 when he succeeded in having the government's controversial military justice system declared unconstitutional.