Hillgrove, who has handled PR for BBC show Dragons' Den businessmen James Caan and Duncan Bannatyne, is accused of failing to pay £93,000 in VAT and PAYE.
The trial originally started last July but was aborted by the judge, who imposed reporting restrictions on the case – now lifted – so that new jurors could not be influenced in the intervening months.
Hillgrove, who is representing himself, pleaded not guilty at the initial hearing and the restart yesterday.
Hillgrove's PR clients have also included the daughter of former Ukranian prime minister Yulia Tymoshenko, who was keen to highlight her mother's plight in jail before she was freed by the country's new regime last month.
The case continues.