The advertisements criticise the school's leadership and feature a large image of headmaster Dr Michael Davies with a red cross over his face.

The electronic billboard, which was unveiled on Wednesday afternoon, references the opening line from Jane Austin’s Pride and Prejudice, which Dr Davies controversially quoted in a school publication in 2014.

“Men of Trinity, all in possession of a good fortune – a Trinity education – should heed the opening words of Jane Austen in Pride and Prejudice," the billboard reads.

"It is a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife."

These direct quotes from Dr Davies were published in the Trinity Grammarian, reportedly offending parents and students who identified as LGBTI.

The billboard then flashes to: "Our school is far too progressive and inclusive for your 18th century views".

The billboard on the back of the black truck screams "Trinity Councillors GET OUT NOW!" and includes images of the remaining six councillors with red crosses across their faces.

Trinity Grammar’s council chairman Robert Utter said the truck did not warrant a response.
"We’re focussed on the task at hand," he said.

Parents, alumni and students have repeatedly called for the school council and Dr Davies to stand down over the sacking this month of deputy principal Rohan Brown, which sparked the scandal engulfing the school.

On Wednesday Mr Brown called on his former students to end their casual clothes protest and return to school in uniform.

Hours before the billboard was launched, Dr Davies received a glowing endorsement from his former school, St Kevin’s College in Toorak, and its overriding body Edmund Rice Education Australia.

A message circulated among the St Kevin’s community said Dr Davies and his family remained “deeply respected and fondly regarded members of the St Kevin's College community and the broader Edmund Rice Education Australia family”.

Dr Davies worked at St Kevin’s from 1996 to 2013.

“His final position was that of Deputy Headmaster which he carried out with distinction, exercising good judgement and compassion. Student and staff welfare was always uppermost in his mind and reflected in his actions,” the statement reads.

It was signed by Edmund Rice Education Australia executive director Wayne Tinsey and seven people with senior roles at the school, including headmaster Stephen Russell and board chair Peter Leahy.

In an attempt to quell the chaos at his old school, Rohan Brown has emailed the school captain and four vice-captains and said he'd like them to wear the uniform for the remainder of term.

"I would like the boys to walk proud and tall, in uniform, to and from school and at school," he wrote.

"Your strength of character, love of the school and leadership is very evident and I would wholeheartedly support you ensuring the boys are back in uniform.”

In protest at the school council's decision to sack Mr Brown for cutting a boy's hair on school photo day, some students have been ditching their green and gold blazers for casual clothes. Last week, they also staged protests at the Kew private school.

Mr Brown thanked the boys for their support.

"May I please thank you and the boys for your wonderful support over the last week. It must be very trying, confusing and difficult for the five of you," he wrote in the email.

He urged the students to focus on their schooling, including VCE assessments, tests and sporting events, and said they were welcome to visit him "today, tomorrow or any day".

At a heated parents' association general meeting on Tuesday night, Fiona Connor lost her position on school council and was replaced by Lisa Williams.

At one point during the night, a parent accused the association of having no backbone and failing to represent the school community. "They are conflicted and puppets," the parent reportedly said.

The school has asked former Federal Court judge Ray Finkelstein QC to investigate Mr Brown's dismissal. Parents who attended the meeting raised concerns about the cost of this review.

The Old Trinity Grammarians' Association has initiated the first stages of its legal battle against the school with a mediation session set with the school council on Monday.

Old Trinity Grammarians committee member Tim Sharp said this meeting was initially meant to take place this week, but the council postponed it.

"They are trying to stall this,"Mr Sharp said.

"We are very disappointed that for all the disarray that the school is in at the moment, school council members do not even think it is a high enough priority to meet this week. Where are their priorities?"