Requiring pupils to have shown climate action interests before striking this week is "preaching to the converted'', a Dunedin school principal says.

Pupils across the country will strike from school on Friday to urge greater climate change action.

Dunedin's Strike 4 Climate will be held in the Octagon.

Many schools in the city will allow pupils to attend with parental permission.

However, most have placed restrictions, such as needing children to already be part of environmental groups or have otherwise expressed interest in the topic.

Heidi Hayward, Principal of Dunedin North Intermediate. Photo: ODT files

Dunedin North Intermediate principal Heidi Hayward said the approach was a "missed opportunity''.

"It will be a bit like preaching to the converted if the only children to attend the rally are the representatives of the enviro-groups, or those already committed.

"We actually need the less active kids to be inspired by their more active peers, who have been bold and proactive in organising this rally.''

Social action fitted well with the school curriculum, she said.

"Personally, I can't think of a more important issue for kids to get active about ...''

She was surprised at the negative reactions to allowing children to strike during school time.

Otago Boys' High School rector Richard Hall said many Dunedin schools had discussed the rally and opted for similar requirements for pupils attending.

His school required boys to already be participating in its environment group.

"While we don't expect them to write reports when they get back, we do expect them to be able to talk about it in a meaningful and purposeful way,'' Mr Hall said.

The school did not want pupils who were not interested in the topic using it as an excuse to not attend school.

"We're rewarding those boys who have already shown a passion for it.

"We wouldn't take the whole school down to a cricket game at the University Oval hoping that those kids would suddenly get interested in cricket.''

Two pupils who were passionate about the cause would report back about the rally at a school assembly.

Otago Girls' High School principal Linda Miller said the school wanted pupils to have an interest and dedication to the environment before attending.

They did not have to be in the environment group, but the school asked them to attend an enviroschools meeting so they knew the organisational arrangements for Friday.

Pupils were expected to report back to the school about the rally.

jono.edwards@odt.co.nz