Inspired by Swedish teen activist Greta Thunberg, the protests will be held in over 1,300 towns in almost 100 countries, including in Ljubljana, Maribor, Koper, Novo Mesto, Ormož, Slovenske Konjice and Kamnik.

"We are not going on strike in order to miss classes. We are getting involved and this is not a one-off event," Gala Alica Ostan Ožbolt told the press ahead of the protest.

"This is an important opportunity for us, young people, who are often being criticised for being passive, to show that we aren't," said Ostan Ožbolt.

She noted the good response at preparatory meetings, saying that more than 200 active members of the Youth for Climate Justice testified the young were serious about their demands.

"It's not just a protest. We have set out demands, we have a content group and a PR group," she said.

"It's the most important issue of our time," Atila Urbančič said, adding that the movement would summarise their demands into four major ones.

Their prime demand is action to immediately decarbonise Slovenia to comply with the target of limiting the global rise in temperature to 1.5 degree Celsius compared to the pre-industrial age increase.

Urbančič welcomed the support thrown behind the youth protests by the Environment Ministry today, but said that it was still to be seen whether they would be received by government officials on Friday.

The movement also includes primary school children. One of them, Voranc Bricelj, accused the politicians of doing too little for the country and the world at large. "They promise too much and do too little."

Youth activists are also happy about the support of their schools with most of primary and secondary schools reacting positively to their initiative, offering their help.

However, the youth movement has not called on schools to excuse the students who take part in the protests from class, nor has the Education Ministry issued any instructions.

The ministry expressed support for the youth activities in the field of environment protection, but said that it was schools which were responsible for organisation of classes and excusing absences.

"We believe the schools will find a suitable way to place this absence within the excusable reasons for the student's absence," the ministry said.

Poljane Grammar School headteacher Bojan Bogatec Končan said the headteachers of some of Ljubljana's secondary schools adopted a unanimous position that classes on Friday would be held as normal but that the students wanting to take part in the protests would need to get an excuse note from their parents.

Support for the protest has also been expressed by the teachers' trade union SVIZ, which called on its members to join in, if possible, even together with their students.