Most all Spaniards I talk to, those whom I know speak at least some English, do not have any kind of British accent. But that's not to say they speak with an
American accent but maybe with no (foreign) accent at all.
As a twist to the topic, I have some British friends, both of whom are (nearly) totally fluent in Spanish, but when they speak Spanish to the waiter or waitress or store clerk, I cannot understand a word they're saying for their strong English accent. OR, is that to say, that they speak Spanish with NO foreign accent at all, simply speaking another language with their own voice, one which lacks a foreign accent (foreign to them, that is). But even when they speak in English I sometimes have difficulty understanding them.
Similarly, I have some
American friends who speak PERFECT Spanish but with such a harsh, personal
American accent that it sounds totally weird, much like the parodies you see when
Las noticias del guiñol (Spanish puppets giving daily news in a comedy format) doing American political figures speaking in Spanish with strong
American accents.
Many people say that although they can notice I'm not Spanish (really???
) I do have a fair-to-good Spanish accent. I think I have to attribute that to the
American tongue/accent being more similar to that of the British/English tongue/accent and, maybe, for that reason Spaniards seem to think my Spanish accent is fair-to-good. (not to brag, but I do pride myself on my pronunciation. It's my only fair vocabulary and fair conjugation which needs more work).
Saludos, MadridMan