But despite successfully avoiding a fine or censure over the incident, the Member for Maiwar, Michael Berkman, has still been found in contempt of parliament by its ethics committee. He maintains there is “no basis” for the committee’s finding.

In March last year, Berkman joined thousands at the student strike for climate change outside Parliament House. At one point, the MP helped parliament staff ensure the safety of protesters climbing on fences, before taking his own children into the precinct, his occasional workplace.

But a Facebook photo of Berkman fronting the crowd with his children – as they stood on a balcony above parliament’s sandstone porte cochere with a Greens sign and him wearing an anti-Adani shirt – prompted allegations of disorderly conduct. He denied wrongdoing, however Speaker Curtis Pitt asked the committee to investigate.

In 2000, two former One Nation MPs were suspended from parliament, and threatened with expulsion, after they spilt milk on the steps under the porte cochere during a dairy deregulation protest.

Berkman insisted – in several letters and an opinion from a Queens Counsel – he had not acted disorderly and not interfered with the work of parliament, which was not sitting at the time. He took part in the protest to encourage the students and also emphasise the Greens’ policies of no Adani mine, no new coal, oil or gas projects, and 100 per cent renewable energy by 2030.

“I decided to take the opportunity to go to the Level B balcony, both to show my children the scale of the crowd and to take some photos and video footage of what was, by any measure, a very impressive turnout,” Berkman wrote, later insisting “the matter is a triviality”.

But the committee disagreed, given the prominence Berkman and his children gave to political slogans using parliament as a backdrop, only metres from the Legislative Assembly.

“The committee considered the conduct of the Member for Maiwar did constitute disorderly conduct, notwithstanding that his behaviour was peaceful and not intended to inflame the situation,” the committee found, in a report tabled this week.

The committee took into account Berkman, 38,is only in his first term as an MP and had cooperated with its inquiries. Although his behaviour was unbecoming for an MP, it was not as bad, or potentially criminal, as pouring milk on the parliamentary steps.

Berkman, a former lawyer with the Environmental Defenders Office, has opposed the Palaszczuk government’s extension of protest laws. He used the committee’s report to reiterate his concern Labor and the Liberal National Party had sold out Queensland by supporting Adani.

“The committee can make their finding, but Queenslanders can make up their own minds about what’s fair,” Berkman tweeted, including details for the online store selling the anti-Adani shirt.

In his formal Speaker’s referral to the committee, Pitt explained the issue with protest signs and political paraphernalia inside the precinct.

“Under Speaker’s by-laws, banners, signs or other things that are, or contain matter, associated with a political cause or campaign are a proscribed item and cannot be brought into the precinct,” Curtis wrote.

“They must be left in the custody of an authorised officer. As a matter of practicality, clothing like protest T-shirts have to be removed, covered by a jacket or turned inside out. The rationale for these directions and by-laws is to keep the precinct free of protest and preserve its dignity.”