Swiss Chalet, almost certain that is the brand.They might have been the St Ivel things that @don't tell him pike suggested. They seem to fit the bill in many respects. I never much cared for them as a child and probably still wouldn't.
I do remember now a different variety of Dairylea. I think it only came in oblong tubs. It was more orangey in colour than the usual Dairylea. It might have been called Dairylea Cheddar or something. Apart from a difference in artificial colouring, I don't remember much difference in flavour, or anything else, from the regular stuff.
There must be cheese lovers tearing their hair out reading this.
ETA: These brands ring a couple of bells.
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