Former federal MP Craig Thomson has spent more than four years loudly proclaiming his innocence on fraud and theft charges.

But the now disgraced former politician had nothing to say as a Melbourne magistrate found him guilty of misusing thousands of dollars of union funds for a range of personal expenses, including sexual services.

Now, Thomson has an anxious four-week wait to hear whether he will be jailed for up to five years for his crimes while he was the national secretary of the Health Services Union between 2002 and 2007.

In his judgment, Magistrate Charlie Rozencwajg said it was ''an affront to commonsense'' that Thomson could think he could use a union-issued credit card to pay escort workers, especially when he, as the head of the union, had previously redrafted the code on the use of HSU cards.

Documents show Thomson spent more than $5500 of union funds on escort workers, including $770 for sexual services with an escort worker named Alina in May 2005, which he later claimed back as a ''dinner function''.

Other sex-related payments included $418 to the Tiffany's Girls brothel for 90 minutes in its ''Red turbo spa room'' during a visit in June 2005 and $2475 paid to Room Escort Services for sexual services on one night in April 2005.

A prostitute who worked under the name ''Misty'' later told police Thomson was a regular client in 2007 and that he had lied when he publicly denied allegations made against him.

Thomson was charged with more than 140 offences in total, including theft, obtaining property by deception and obtaining financial advantage by deception.

The Office of Public Prosecutions and Melbourne Magistrates' Court are yet to confirm exactly how many charges Thomson was found guilty of and the number of acquitted offences.

In the wake of the decision, former colleagues in the federal Labor Party said there was virtually no one who believed Thomson was innocent, but many who had feared the pressure he was under could lead him to do ''something stupid''.

Thomson shared a flat in Canberra with former minister Craig Emerson, who was known to be concerned for his mental state as the allegations mounted.

''People thought if he isn't guilty then he's the unluckiest bloke alive, but there was no one I knew that believed that,'' a source said. A former factional colleague noted that while the former MP ''can't be a union official or MP again, he has a great career ahead as an actor''.

Employment Minister Eric Abetz said Thomson misled the Parliament over the allegations and now had a lot of explaining to do.

The magistrate, who convicted Thomson of some allegations related to spousal travel, said there was no justification for him using union funds on cigarettes and firewood for his then wife.

But Mr Rozencwajg conceded there were ''grey areas'' in policies governing use of work-issued credit cards, so dismissed charges related to the purchase of adult movies and some charges related to travel expenses for Christa Thomson.

Mr Rozencwajg also found Thomson guilty of using union funds for his personal use after he had left the HSU, and taken up his role as the Labor member for the NSW seat of Dobell.

Thomson left the court grim-faced and without comment and was heckled with calls of ''liar'' by relatives of HSU whistleblower Marco Bolano, who were angry that the former politician stood before his colleagues and country in 2012 and tearfully denied the allegations, and claimed he was being set up by his political and union opponents.

Thomson had his bail extended, and will return to court on March 18 for a sentencing hearing.

HSU acting national secretary Chris Brown said the union would now seek to recover any money stolen from it.