My experience (lived 6 years in Aberdeen) has been that the Scots, in particular, hate the English.
The average English person will support any of the home nations in sporting events against any other country. If England get knocked out, we tend to switch our allegiance to Scotland, Wales or Ireland, assuming they are still in. On the other hand, Scots (I can't speak for the Welsh and the Irish) will support any team against England. This is a fact which actually really saddens me.
My Dad said once "We (the English) thrashed their arses 800 years ago and they still haven't forgiven us for it." I think there's an element of truth in that, but also I think the Scots have such pride in their nation that it upsets and infuriates them when people of other nationalities lump the whole of the UK under the banner "England", which happens an awful lot - many foreigners think that Scotland is part of England (or, often, have never heard of Scotland).
I was on a course in Edinburgh once and went out with a few drinks with a girl from Inverness who was on the same course. We got on really well until she got a bit drunk and started saying how she hated "The English". I pointed out that she was saying she hated me. We ended up in quite a row, as I was trying to get her to admit that she didn't hate all English people (since she hadn't even met most of them and might actually quite like them, since she claimed that she liked me) and we ended up having to agree to disagree.