Slur Represents Reason & Origins
Bloke British Used by french canadians to identify english speaking people
Brit British Short for British. Used as in "Brits Out!": graffiti from Ireland.
Chinless Wonder British Reference to inbreeding and a weak gene pool resulting in poor bone structure.
Cocks British Short for "cockneys"
Crumpet-Stuffer British They eat crumpets with their tea.
Crumpet-Sucker British They eat crumpets.
Feb British Stands for Filthy (or Fucking) English Bastard.
Fog Horn British A loud/annoying British person.
Fog-Breather British Englands weather is often extremely foggy
Jeeves British A supposedly common name of British butlers.
Limey British The British Royal Navy supplied a daily ration of lime or lemon juice to their sailors to prevent scurvy.
Lobsterback British Redcoats in Revolutionary War.
Pohm British "Prisoner Of Her Majesty". Used mainly in Australia as a derogatory term for British People. Comes from the fact that Australia was a prisoner colony for British Prisoners. Sometimes heard as "Pom"
Pome British 'Prisoners/Property Of Mother England' Used in Australia, New Zealand, etc. Probably related to and/or another version of Pom.
Red Coat British Used during the Revolutionary War, because of the Red coats the British army wore.
Rooineck British South African version of redneck.
Rooinek British This derogatory name was used by the Boers to describe the British primarily after the Anglo-Boer war which lasted from 1899-1902.
Rosbif British Rosbif has been a reference used by the French for the British for hundreds of years - long before tourist holidays. It is a reference to our eating habits, used as a reply to us calling them "frogs" after their habit of eating frogs legs.
Tans British Refers to the criminal army the English sent into Ireland to rape, plunder, and terrorize the inhabitants. The uniform was made up of tanned bottoms and dark upper clothing. They became known as the black and tans.
Tea-wop British Tea-drinking immigrants.
Teabag British British are said to drink a good deal of tea.
Tommy British Tommy Atkins was a fictional soldier used to represent all British soldiers for morale purposes during WWI.

- Origin in dispute.
Wanker British Implies that the addresser is accusing the addressee of self-gratification.