Maybe. But I think it's more football 'banter' than being Tory. We are happy to call them six fingered sister fingered. Hardly embracing them as people.
Personally, I don't talk about Mancunians in that kind of way, but I understand your point. I don't have a problem with piss-taking, whether giving it or taking it, but so much of the stuff they (and the Bitters*) spew out goes way, way beyond anything that could be called "banter". There's no "banter" in jibes over poverty, governmental neglect, unemployment and stadium disasters.
On the whole I find our jibes at United and Everton to be pretty harmless. We might paraphrase Ferguson and sing "Fergie's right, your fans are shite" but their retort is "The S*n was right, you're murderers". One is a harmless piss-take, the other is deliberately offensive and adopts the Tory establishment party line since 1989. This pretty much highlights the difference in mindset between the fanbases. Theirs is a long way past banter. Apart from singing '20 times' I see very little from them you could regard as football banter. The overwhelming majority of it is bile based in politics and social issues. The irony of that is stark when you realise the communities these people also come from.
*I reserve the "Bitters" title for their lunatic fringe, not the decent blues out there.