Captain Britain > "ohhhhh.....you've spotted my dickey"
Captain America > "Christ! you're soooo damn.....British!"
Captain Britain > "Spot of tea govenor?"
Captain America > "oh screw this! Here, take the shield, take the tights, hell.....take the name....I'm going to Papa John's for some deep dish"
Captain Britain > "fight like a man...chap!"
Captain America > *while walking away* "call me when you find out how to be one..."
Cor Blimey! Guv'nuh!
If you mean Union Jack, Cap could take him. Captain Britian, well he might be able to take the new one down, unless she hits him with an energy spoon!, the old one, being that he's a GOD and all will probably beat Cap.
But what if we lend Hauptman Deutchland, Red Guardian and Major Mapleleaf to the fight?! Oh no! Clash of the rampantly patriotic country themed heroes!