Counter-demonstrators have notified Helsinki police of their intention to hold a protest in the Finnish capital aimed at Extinction Rebellion activists.
The rival demonstrations are scheduled to begin on Wednesday.
Panu Huuhtanen, a local election candidate who got 47 votes in Vihti in 2021 who has also been involved in protests against immigration and Covid restrictions, announced on Twitter that he intended to protest against Extinction Rebellion.
The Extinction rebellion protest is scheduled to take place on Mannerheimintie, the capital's main thoroughfare, for ten days.
Police said the planned protest could cause significant disruption to traffic.
Police noted that they had asked the demonstration's organisers to move to a site off the main road, but they had declined. Police are legally able to stop marches or end demonstrations if they believe they contravene the law, endanger public safety and order or blocks traffic.
Last September, Extinction Rebellion blocked traffic in front of government offices on Snellmaninkatu, and they stopped traffic on Mannerheimintie in June.
In October last year police pepper-sprayed activists in Kaisaniemi after they had blocked traffic for several hours.
Extinction Rebellion are demanding that the government declare a climate emergency and move climate action forward to aim for carbon neutrality by 2025.
This article has been edited to add details about the counter-demonstration's organiser.