If he objected to the Queen's role as head of the Church of England he could, but other than that I can't see any reason why he should unless he's anti-royalist.
Would it be fair to suggest that the national anthem does not represent the thoughts, hopes and aspirations of patriotic atheists?
A republican of any creed would not swear allegiance to monarch or sing their praises.
Depends how you phrase it : 'God save our gracious Queen..' or 'God ! Save our gracious Queen...' The latter is despairing, addressed to the people, not to a deity, and a Christian might call it blasphemous.
oh sorry Mark Rae......how silly am I...........maybe they could go......mmmmm save our gracious queen.......mmmm save our noble queen......mmmm save the queen....
I think a lot of atheists would sing along simply out of a sense of national pride and respect for the queen, but go on then, Everton. I'll go along with you. Who's this hypothetical atheist?