The whole idea of "military" tribunals came from the UK which were used during "the Troubles" and are still in place.
No, they aren't. Interment of Irish nationals still had to be under the assumption of criminal or terrorist intent, and could be contested even in the 70's.
The laws where changed during the 80's and 90's and eventually dispanded altogether with the Good Friday Agreement.
The UK Terrorism Act of 2001 does provide certain detainments but only under the guidelines Emilia posted. And those apply universally, no one ethinicity can be targetted, even if they do at times harass Muslim minorities more.
But since the Republic of Ireland is now a member state of the European Union, even if the Irish Internment law was still technically allowed on the books, by simple principle of supercedence, the newer human rights acts of the UK and EU would allow anyone detained under it to appeal immediately and be released under unlawful detainment.
There is no standing UK law other that the TA2001 that allows someone to be picked up, and there are a lot of caveats to that law, human rights must be observed, they must prove terrorist intent, and be released immediately if none is found.
Until we open our own international concentration camp to hold prisoners indefinitely without any human rights such as the Gitmo facility, please don't imply that holding someone for 24 hours in a cushy room is equivalent or somehow an even greater "fascist" movement.