In UK the law re pedestrian crossings is that a pedestrian USING the crossing has precedence.
That means AS SOON AS A PERSON HAS PUT A FOOT ON IT. Not when they are standing on the footpath looking at the crossings. And that also include a pedestrian who gives drivers no indication that they about to use the crossing.
Note- Vehicle drivers are obliged to give way only to pedestrians, so not cyclists, skateboarders etc. who are using the crossing to cross the road, they have no right of way over vehicles.
PS The same applies in Spain and probably elsewhere in the EU.
And, just in passing: Whilst probably all drivers know they must not park on a crossing, they should also not stop on a crossing when they are in congested, slow moving traffic. Drivers failing to do that were a particular problem to me when I was a young PC on school crossing duties. It meant I had difficulty ensuring that school children, whom I had to lead, weaving through the stopped traffic, were safe.