Defence barrister John Agius, SC, told the ACT Magistrates Court on Wednesday that key elements of the offence of blackmail had not been covered in a police statement of facts setting out the allegations against Mr Lomax.

Outside court, the silk revealed he had written to the Office of ACT Director of Public Prosecutions to invite them to withdraw the charge.

"I think the prosecution case is doomed to failure," Mr Agius said after the the union organiser's first appearance.

"We await service of the brief, but the matter will be vigorously defended.

"The sooner we get served with the brief, the sooner we can deal with it and this matter can go away."

Mr Lomax, 49, was arrested and charged with one count of blackmail during the Canberra sittings of the royal commission into unions last month.

He entered pleas of not guilty when he appeared before Special Magistrate Maria Doogan on Wednesday.

The Construction, Forestry, Mining and Energy Union has said he would have its full support in fighting the allegations.

Police will allege that Mr Lomax forced a Canberra painting company, Nel Trading, and its principal, Woong Yul Park, to sign a union enterprise bargaining agreement in April last year.

The owner allegedly believed he would be blocked from working in the ACT and NSW if he did not sign.

It is understood police will allege the owner suffered a financial loss as a result because the EBA required him to pay his workers $26 an hour, when he claims he could have paid as low as $17.

In court, Mr Agius successfully sought to have Mr Lomax's bail varied so he could continue his work as a union organiser without fear of inadvertently breaching the conditions while visiting building sites in the course of his employment.

"The bail conditions were hopeless, they prevented this man from attending to his daily work," Mr Agius said.

"Mr Lomax has no intention or desire to approach any of the persons named in the bail form, we're not sure of the relevance of some of those persons.

"But as they were, the conditions … prevented from him attending to his work, now at least he can get on with life."

The matter will return to court in October.

Earlier, Mr Lomax was given a guard of honour by CFMEU supporters as he entered Canberra court on Wednesday morning.

More than 100 vocal unionists gathered outside the Civic courthouse to chant slogans in support of the under-fire union official.

In the Legislative Assembly, ACT Planning Minister Mick Gentleman slammed the commission proceedings during a debate on Wednesday.

"It's my understanding this royal commission does not afford natural justice and fails to provide union witnesses natural justice by making serious allegations without giving them the proper notice and not allowing witnesses to properly respond to the allegations made," he said.

Mr Gentleman said procedures used by the commission "were more reminiscent of a show trial."

The comments came during debate on an unsuccessful opposition motion calling on ACT Labor and the ACT Greens to end political cooperation and donations from the CFMEU.

Opposition Leader Jeremy Hanson said Labor members wore the party's handling of the commission proceedings as "a badge of honour".

A statement from UnionsACT said the appropriate legal tribunal for the Lomax matter was the Fair Work Commission, not a criminal court.

UnionsACT secretary Alex White said in the more than 80 years of Australia's industrial relations system, there had never been an instance of criminal charges being laid against a union official seeking to exercise their lawful, legitimate right to collectively bargain.

"Working people should be very concerned at the potential precedent that these charges pose," Mr White said.

"Seeking to enforce an existing collective agreement, and to secure better wages and conditions, is not a crime.

"The appropriate venue for this issue to be resolved is the Fair Work Commission, and I hope the Magistrates Court quickly determines that this is a legitimate industrial matter."

CFMEU national construction secretary Dave Noonan said Mr Lomax had been charged for securing a pay rise for workers that resulted in a financial loss for the employer.

Mr Noonan said the use of criminal law in answer to negotiating a pay rise heralded a dark chapter in Australian industrial relations as it went against the legal framework that has operated in Australia for more than 100 years.

"There are very clear laws pertaining to industrial matters in this country with rights and responsibilities for unions and employers," he said.

"The criminal charge against Mr Lomax is unprecedented and a disgrace. It is an attempt by Tony Abbott's royal commission to use criminal law in order to prosecute a union official for lawful industrial activity.

"Asking for a pay rise on behalf of workers is not a crime, but it appears that Tony Abbott wants to make it one."

Mr Noonan said the CFMEU intended to fight what it labelled a direct attack on the union movement's ability to protect wages and conditions, and pledges to back Mr Lomax.

"We intend to fully support Johnny Lomax, but this case reaches beyond Mr Lomax or the CFMEU.

"This is about every unionist in Australia who, if Tony Abbott has his way, risks a criminal charge for doing nothing other than advocate for higher wages for their members.

"Every person concerned about the democratic right and legal protection of workers to bargain for better pay and conditions should be alarmed by this case."

Mr Lomax played 65 games for the Raiders from 1993 to 1996, and won the club's player of the year award in the 1994 premiership-winning season. However he missed the 1994 grand final due to suspension.

Mr Lomax then moved to the North Queensland Cowboys and finished his NRL career with the Melbourne Storm.

- with Tom McIlroy