That many other (EU) countries who have implemented the EUHR directive deport asylum seekers to other countries, and those countries SC equivalents have not found it to be illegal.

I guess my legal basis is precedent.

Your legal basis on which you base your opinion on U.K. law is (supposed) precedent from countries that are not the U.K.

Forgive me if I find your entire premise suspicious and decline the opportunity to debate further.