I doubt if there are laws about queuing in any country - but in mine, if you cut the line, be prepared to be smacked (at the very least, if you're local or not).

Here, people "give way", I refuse to, my time is valuable to me - if you ask, usually I'll let you go if it's one or two items and I have a trolley load. If you don't I have no qualms about sending you to the back of the line. Call the cops, see if I care.