PGCE as proof of language

Good evening,

I am a French national with a degree obtained in France a long time ago. I then married a British citizen in 2006 and in 2012 I studied a PGCE (Post-Graduate Certificate in Education) in a British university to become a secondary teacher, which is what I currently do for a living.

My question is: can my PGCE (which is a higher qualification than a degree) be used to prove my knowledge of English?

I would appreciate a reply from people who have successfully done the same (used their PGCE as proof of their knowledge of English) as I am reluctant to take another test of English (which I already did to be able to study my PGCE 10 years ago).

Many thanks,