Asked if he would be fighting to push the bill through, Mr Swinney told Sky News: "The reality of the situation we face is that the Supreme Court has said that we can't legislate in that area. We can't take forward that legislation."
His predecessor Humza Yousaf had previously suggested he wanted to work with the UK Labour Party to amend the laws ahead of the general election.
https://news.sky.com/story/scotland-could-be-independent-in-five-years-first-minister-john-swinney-says-13132650
Which I take to mean he isn't against the GRC just that the UK Government has the upper hand.
I was (still am) more worried the with Labour in power the UK wide laws will be ammended so that the GRC will not be out of line.