It will affect your licence as if in the worse case scenario all UK ETSOs, EASA Form 1s, type certificates, MRO certifications will become invalid. Also the same applies in Europe to a lesser extend. Many UK maintenance personnel work in European countries and companies and many Europeans work in the UK aviation industry.Nothing will fly on either side of the fence and it won't matter what colour your licence is.
Items 1, 2, and 3 are pertinent reading in the link below:
https://ec.europa.eu/transport/sites...ion-safety.pdf