US lawyers are braced for further federal scrutiny of their ethical standards after the US Senate demanded an investigation into the role of law firms in tax evasion – with Sidley Austin Brown & Wood already facing stiff criticism for its role in promoting tax shelters.

The Senate subcommittee report, issued on 20 November, called for the US Department of Justice and the Internal Revenue Service (IRS) to jointly investigate tax shelter activities at US law firms following a year-long study.