What you mean to refer to is priority. Pedestrians have priority when they have started to cross the carriageway (at least) at junctions. See Highway Code Rules 8 and 170. I'm no legal expert and don't know on which legislation this is based (Road Traffic Act?) or if these rules apply generally and not only at junctions.
For everyone's information, the concept of 'right of way' has a different meaning from the one you intend:
https://en.wikipedia.org/wiki/Right_of_way
What you mean to refer to is priority. Pedestrians have priority when they have started to cross the carriageway (at least) at junctions. See Highway Code Rules 8 and 170. I'm no legal expert and don't know on which legislation this is based (Road Traffic Act?) or if these rules apply generally and not only at junctions.
http://www.highwaycodeuk.co.uk/uploads/3/2/9/2/3292309/the-official-highway-code-with-annexes-uk-en-12-04.pdf