Former union boss Michael Williamson has pleaded guilty to fraud in relation to his conduct as head of the Health Services Union (HSU).
The former HSU and ALP president faces jail after being committed for sentencing on four charges in Sydney's Downing Centre on Tuesday.
The charges include cheating and defrauding a total of almost $1 million as a director and publishing false invoices.
Williamson is also charged with recruiting others to assist in a criminal activity and hindering a police investigation by destroying Amex statements.
He had originally faced more than 50 charges, which will be taken into consideration during his sentencing.
The charges followed an investigation into corruption allegations in the NSW branch of the union which had been raised by national secretary Kathy Jackson and others.
Williamson resigned from his posts at Unions NSW and the scandal-plagued HSU in April 2012.
He was charged last October after police raided his home.
Magistrate Graeme Henson ordered Williamson to return to court on October 25 when a date for his sentencing will be set.
If found guilty of all charges he could face more than 30 years in jail.
