The initial move against this "power grab" is that the Scottish govt will refuse to pass what is known as a legislative consent motion on the IM bill - such consents are normally required for the UK Parliament to pass laws that involve devolved matters, which this bill does. A vote will be taken in the Scot Parliament against this consent and Scot Labour and the Green Party support that refusal and will provide a big majority in the Holyrood Parliament to refuse consent. IMO it is an existential issue - yep, as serious as that!! What will certainly follow will be a confrontation in the law courts. Should the Brit govt win that legal battle then I agree that the Treaty of Union has been violated and we finally tell them to "shove it". However, I suspect the SNP/Scot govt will take a "softly softly" approach v a real bunch of "dirty tricks" Tory chancers - they are "wise" to these c#### and don't underestimate their ability to move things politically in a democratic and constitutional sense up to a point of no return when the huge indy movement will finally and seriously be mobilised to take action.