Ridiculous.
Within law has nothing to do with right or wrong. If what they have done is illegal the law needs changing. Its 2017 flecc. Not 1817.
Treason and sedition when no one has been harmed ( except folk voting by GC) are government constructs. Imaginary crimes.
They believe in independence and asked rest of "their" nation. Your position on this could justify civil war. Its already justifying prison sentence. Its wrong Flecc.
South Africa justified imprisonment of Nelson Mandella on similar grounds. What he did was illegal in their constitution. I suppose theirs was wrong and Spains right ? In your opinion???
Every society and state has laws , it didn't matter whether they are democratic, autocratic, dictatorships , left, rightist, fascist or whatever .
I doubt whether these two persons were imprisoned for wanting their choice of independence, or for their beliefs. What they have been imprisoned for would have been for their actions. And the expectation that they would continue to so do.
In this case was it not that they were the identified leaders of large group of people ( I am on purpose not using the word mob) which prevented the national police from leaving their barracks?. Even in liberal London or Dundee , the action of impeding the police is an offense, is it not?
It would appear that the chief of the local police, who as not been arrested, is under investigation over the same action. , In that he did not act to release the national police. Now he also has a duty for public safety, and he may have formed a judgement that public safety, was more pressing....and had he acted in accordance with the law the group might well have become an uncontrollable mob.
Had the action of the national police been to lock up anybody with "independence" , ideas , then it would have been internment.... But you know nothing about that in the UK.
Please note that there is no action pending against those courageous firemen, who acted to keep the much larger group of civilians, separated from the much smaller, but more heavily armed police, in another incident.
To equate their actions ( the two arrested )with that of Mandela, is somewhat extreme. The Catalans do and did have the vote. The same case not true in south Africa.