Ulez

You can try and buy a Spanish sticker over the counter at a post office there, though as of last year they were not selling them for foreign registered  vehicles, so personally I reckon your French sticker will do for Spain. 

Portugal only wants them in Lisbon itself and I doubt  if you will be driving there. 

But if you want a more official answer you should type “ CAMC lez Europe “ as a Google search and you will find detailed and thorough information from Club hq. 

I think it is accepted in Spain no idea about Portugal.

peedee