Language requirements for postgraduate studies in UK and Canada? Universities are autonomous institutions with independent requirements and decision making procedures, on the other hand there must be some widely recognized standards.

What is the most recognized English language certificate for postgraduate (physics) studies in UK and Canada universities? 

P.S. EU citizen
IELTS is widely accepted in the UK, and it is also accepted by the UK immigration authorities.

ToEFL is also widely accepted by universities but is no longer accepted by UK immigration authorities.