I can't stand people who keep bad mouthing Scousers. My dad worked in Liverpool for nearly 20 years and never had any trouble with the locals. He was a tail - gunner on a milk float.
A customer asked, "In what aisle could I find the Irish sausages?" The assistant asks, "Are you Irish?" The guy, clearly offended, says, "Yes I am, but let me ask you something... If I had asked for Italian sausage, would you ask me if I was Italian? Or if I had asked for German Bratwurst, would you ask me if I was German? Or if I asked for a kosher hot dog would you ask me if I was Jewish? Or if I had asked for a Taco, would you ask if I was Mexican? Or if I asked for Polish sausage, would you ask if I was Polish?" The assistant says, "No, I probably wouldn't." The guy says, "Well then, just because I asked for Irish sausage, why did you ask me if I'm Irish?" The assistant replied, "Because you're in Halfords."
Technically yes to some people. Not to me. For me you can joke about a persons origin/race/colour without it being offensive. It's the intent that counts. But I don't want to start a big debate on here, I just wanted to state my view, please, please, please don't respond to this. Edit: It obviously depends on the joke too.