[3][4][5] Williamson rose to prominence as an official of the HSU, representing the interests of low-paid workers in the health sector in New South Wales and then Australia.
During his term as national president he controversially merged the NSW and two Victorian branches of the union to create HSUeast.
[9] Williamson was also a vice president of Unions NSW until April 2012, when he resigned after being asked to explain to its executive why he should not be removed.
The media report detailed that Williamson was a director of a computer company, United Edge, that provided information technology services to the HSUeast branch, without going to competitive tender.
[22][23] On 4 October 2012, Williamson was charged with more than 50 offences relating to fraud and obstruction of justice, and was suspended as director of United Edge.
[24] Appearing before the Sydney Magistrates Court on 15 October 2013, Williamson entered a guilty plea to four major charges related to cheating and defrauding HSUeast, creating false documents with the intention to deceive and the recruiting of others to hinder a police investigation.
Prior to his guilty plea, the union and Williamson reached agreement on the terms of settlement via mediation supervised by Robert McClelland, a former Labor Attorney-General.
The Court will determine the penalty I am to receive, but it won't remove the fact that I have to live with the matter until the day I die.