Neither Sweden nor the UK will or can do such a thing as it's a violation of EU treaties to do so.
As the UN panel notes this is in violation of the very treaty you cite. This is precisely the fear and it is clear the fear is reasonable and well founded in fact. The UN findings are unequivocal.
If they're willing to go that far I really don't know why they don't just let him go to Equador and have him assassinated there, it would be a whole load easier.