Ok small and big minded people on this site, lets deal with the facts. There are different types of "bus stops" and there are situations where it is legal to park in a "bus stop". In parts of the UK there are community spaces for parking in high traffic or constricted road width venues. In my own case there is a bus stop at the end of my road, that is at the corner of 3 roads and a set of traffic lights.
The situation here is that bus stop has broken yellow lines around it, and is at the end of a permit parking section of a road. The law is very clear, you are entitled to park in bus stop, provided it is not a "restricted" bus stop. Restricted will be marked by a solid yellow line at the entrance to the spac and normally marked with either a thick yellow line, or double yellow lines.
Where the bus stop has a broken yellow line around its perimeter, and no single or double yellow lines, it is not a "regulated" bus stop, and thus is treated like an unmarked piece of road. This is also known as a community bus stop, or pull in.
The act is the 1991 Road Traffic act, and this issue is covered under the PCN 49 part of the code around enforcement and adjudication.
So to be clear, check if it is a "regulated" bus stop, then you know if you have an appeal.