Traditionally England does not use Monday as the start of the week. This is easy to see if you look at older calendars.
At the moment there's some inconsistancy:
Sunday to Saturday: https://www.gov.uk/maternity-pay-leave/pay
Monday to Sunday: https://www.gov.uk/guidance/statutory-sick-pay-manually-calc...
Googling for ["sunday to saturday" inurl:gov.uk] or ["monday to sunday" inurl:gov.uk] shows a bunch of examplesof each.
EDIT: You asked for links, so here's something from 2009 asking why it's so hard to find a calendar that starts on a monday: http://www.theguardian.com/notesandqueries/query/0,,-200944,...
> Why is it so hard to find a calendar that starts the week on a Monday, not a Sunday? It can't just be my family who gets outraged by this.
And here's something else from 2009 which (weirdly) explaining why it's so hard to find calendars that start on Sunday, not Monday.
http://www.telegraph.co.uk/comment/letters/6495398/Officiall...
tl;dr England used Sunday as the first day of the week until they started using ISO standards for time.