The Fredericton superintendent who cancelled a class visit to a Justin Trudeau rally defended his decision on Friday, citing its "partisan nature."

Grade 12 political science students from Fredericton High School were to have attended Trudeau's public meeting on Tuesday as a learning experience.

But David McTimoney, the Anglophone District West superintendent, cancelled the school's involvement this week.

McTimoney at first declined to be interviewed, but explained his decision Friday in an interview with CBC News.

"When we expose students to activities to promote their civic engagement, we have a responsibility to ensure it is a balanced view. For this case this was a rally, a rally of a particular party that was an attempt to gain support," he said.

He said he had given a lot of thought to the idea of allowing the students to attend the federal Liberal leadership candidate's event in the capital city.

"My initial position was that it could be an educational experience for our high schools students," he said.

But after further reflection, conversation and examination of the rules surrounding such events he changed his mind.

"The determination was made that indeed this wouldn't be an event that a school district or a school should be facilitating, due to its partisan nature," he said.

He cited Regulation 97-150, section 29-1, under the Education Act to bolster his decision.

"It talks about political party activity, or political party symbols, not being a part of school exercises," he said.

Trudeau was in Fredericton to bolster his bid to lead the federal Liberals.

Asked if attending such events could be viewed as a core part of the social studies class, McTimoney said the rally didn't meet that criteria. He praised the students as critical thinkers and spoke with them about the issue at length.

"We do support opportunities, but they need to occur in a balanced way," he said.

"A school can't be responsible for facilitating an event that is a single, partisan view."

McTimoney said if Stephen Harper came to town to speak as prime minister, he would allow the school to send students to the event. But if Harper came to urge people to vote Conservative, he would not permit it as an outing.

Lost opportunity

The audience to see Liberal leadership candidate Justin Trudeau consisted of a mix of ages. (CBC)

Many students went to the Trudeau rally own their own.

Tom Bateman, a political scientist at St. Thomas University in Fredericton, said cancelling the official class visit was a lost opportunity.

"Parties, their internal operations, their interaction with parliamentary reforms, are part of learning about the political process in Canada," he said.

He suggested teachers could have prepared students to examine the rally critically, asking questions about the socio-demographic profile of the participants and how Trudeau handled questions.

Bateman said it was a tough call for the superintendent, but said the distinction of students attending as observers, not participants, tipped the balance toward their attendance at the Trudeau rally.

"If the teacher encourages students to attend the Justin Trudeau rally, then the next time the Green party holds some kind of public forum ... make sure the students get there, too, so they can have a comparative exposure," he said.

He said examining many rallies from different parties could have helped students develop a better understanding of various political groups and their supporters.

However, Dennis Cochrane, a former deputy minister of education and former leader of the Progressive Conservative Party in New Brunswick, said the district made the right call by withdrawing support for the event.

"I don't think it's the responsibility of the school system to provide an unbalanced situation by making it mandatory or making it an opportunity for those children to go to that kind of event," he said on Friday.