Clare Sibson KC is a leading silk and considered one of the brightest legal minds at the Bar. “Fiercely intelligent with a lot of emotional intelligence as well, so clients love her. She really fights her corner for them.” She is a prescient tactician, and her cross-examinations are renowned.
For over four years following the collapse of Carillion PLC - the largest liquidation in UK history – Clare advised and represented Richard Howson, the company’s former CEO. She successfully defended John Varley in the first Barclays-Qatar trial, Colin Bermingham in his first Euribor trial, and Rebekah Brooks in the nine-month phone hacking trial. She advised Sir Cliff Richard in relation to the now closed South Yorkshire Police investigation and she represented Robert Tchenguiz in his successful High Court challenge of search warrants, following the collapse of the Kaupthing Bank. In 2011, she represented David Mabey on charges of UN sanctions violation.
In corporate law, Clare brings depth of experience to litigation at the intersection between contractual obligations, directors’ fiduciary duties and criminal and regulatory risk. In May 2023, she defended a large bank in a chancery action to redeem the security for a €1.15 billion, syndicated loan. In 2021, she represented Petrofac Ltd before the Crown Court in relation to a ground-breaking plea agreement for failure to prevent bribery in three jurisdictions. In 2020 she was, as a criminal specialist, the first port of call for the operator of a major transport franchise agreement, on discovery of irregularities in its accounts. In 2018, she advised Deloitte in relation to the FRC’s investigation of its audit work for SERCO. In 2017, she represented Tesco in DPA proceedings; in 2015 she successfully defended Gyrus Group and Olympus Corporation on Companies Act charges at first instance and on the prosecution’s appeal. In the noughties, she represented the FSA in relation to the Shell Oil Reserves Scandal, and she defended pharmaceutical group Ranbaxy - from the Magistrates’ Court to the House of Lords - in the SFO’s failed attempt to prosecute alleged cartel activity under the common law.
Clare has an advisory practice involving matters such as insurance arrangements, mergers, securities trading, and trade secrets. She advises Big Tech on forthcoming online services legislation. In the past, her work has included giving real-time advice on anti-terrorist legislation in the context of live negotiations for the release of hostages.