McSweeney fundraised for Labour Together during his role as company secretary, though stopped reporting the large majority of donations the group received from December 2017 onward, eventually failing to report more than £730,000 in funds within the 30 days required by law during his tenure. The undeclared donations as well as additional incorrect information declared by McSweeney were investigated by the Electoral Commission; Labour Together received a fine of £14,250 for over 20 breaches of electoral law in September 2021, which a spokesman for the Commission stated was "towards the high end of the scale".