For the record, political strikes happen in the other Nordic countries as well. According to a quick search on the Internet, the only Nordic citizens who are _not_ allowed to partake in a political strike are public servants in Sweden.
In other words, political strikes are effectively banned i Sweden.
I'm not aware of any exception to this rule for public servants but I could be wrong.
The Nordic countries all have certain restrictions on striking for some groups of public servants. The groups vary and the restrictions do, too. If I read my book correctly, Sweden forbids key officials (those who have certain positions of authority) from participating in solidarity strikes (strikes in support of others), unless those others are also public servants.
https://books.google.se/books?id=IYx2GZdMA7AC&pg=PA37&lpg=PA...
The purpose of the law is to prevent certain tempting corrupt practices.
As far as I know, this law has never been used, but I feel like it is sensible.
Note: 99% of the time, like all Swedish workers, those officials have a binding collective bargaining agreement, so are forbidden from striking anyway. (I e if they go on strike, they may be legally fired.)
Not exactly true. What you're talking about is the industrial peace obligation inherent in each collective agreement. But this obligation is not applied where the strike has nothing to do with the collective agreement, i.e., where the objective of the industrial action is not covered by the collective agreement. This is precisely the case with political strikes. In this respect, the system is very similar to that in Finland. However, AFAIK, there are other limitations to purely political strikes, see the source below.
At least this source [1] states that 'purely political strikes are, in most countries, at least in theory, prohibited, exceptions being Denmark (if short and for “reasonable cause”), Finland, Ireland, Italy and Norway.'
Looking more carefully at that source you will find, however, that there is, in practice, a lot of room for strikes of varying political nature in many more EU states.
[1] https://www.asi.is/media/7581/Strike_rules_in_the_EU27.pdf
So yeah, strikes are perfectly legal.
I just wanted to give especially Americans some view on how different things may be.
According to my search as an example in Denmark they're only allowed if "Short and for reasonable cause" and so forth and sweden was not listed at all, but norway was. This is likely a mix of case law and actual written law. https://www.asi.is/media/7581/Strike_rules_in_the_EU27.pdf
Finland is probably one of the few places where you can't fire an employee for participating in a poltical strike. The ability to fire someone for going on strike doesn't make the strike illegal though.
So even if Finland would make political strikes illegal it would not change much.