Short for Change UK, formed on the day when Brexit was finally supposed to occur.
Apparently their idea of change is no change, as in no Brexit.
Looks like the woman in the center realizes their mistake, but that's probably just wishful thinking.
Any seat in Parliament kept by one of these in the next election one wag says will constitute a CUK-hold, but they all already have made cucks of the people of the UK they represent. It is an odd fetish, thankfully, enjoyed by but few, less than 2% of the UK's constituencies.