I'm not sure if I'm one of the 'marxist, woolly true huggers' that you're addressing (given that I'm not a marxist, and as far as I know only ruby27 openly declares herself a marxist), Bewlay, but I am pro-immigration and sceptical of the hysteria surrounding Islam, so I suppose I can answer.
To be honest, I think it's rather daft to predict an uprising or civil war at all in the modern UK. Public opinion has been far more bitter than it is now in 1989-90, 1973-4, mid-30s, 1912-14, and the only times I'd say we've ever really come close to violence or revolution - the 1840s, and 1832. There was no civil war or uprising in any of these instances, and the simple fact of the matter is that while there's division and fierce argument over certain issues, it's not any worse than it's been in the past.
But I digress.
Your question was on islamophobia. There's pretty widespread misconception about Islam, as the vast majority of scholars on the subject will tell you - such as (I have notes buried somewhere on a lecture I attended on the subject by a scholar who gave quite an enlightening view on this with specific reference to the Koran, I can try and dig them up when I have time, and I'll also dig up some sources to support this if I get time).
The worst excesses of Islam are truly no worse than the worst excesses of Christianity, but whipping up fear over Islam is something that's extremely easy to do - just as it was in the case of the Irish throughout the C19 and with the Jews in the early C20. So I think we are perfectly legitimate in bieng disgusted and condemning of the extremists who seem to spew populist rhetoric and sound more powerful than they actually are (such as Ahmadinejad) within Islam, but we should be equally distrustful of those same figures within our society.