There are two main reasons for this. First, demands from employers have increased enormously over the last 30 years. Weekends have become precious. Two Sunday services are seen as taking up too much of the weekend. Second, back in 1994, the Tory government legalised Sunday trading. This secularised the day, giving people many more options with regard to how we spend it. Simultaneously it put extra pressure on many to work on Sundays.