Under the Sunday trading legislation, stores with an area of over 280 square metres are allowed to trade for up to 6 hours on every Sunday in the year except Easter Sunday (and Christmas Day if it falls on a Sunday).
That means that all big supermarkets, garden centres, DIY stores, department stores and shopping centres (such as Lakeside and Blue Water) will be closed tomorrow. The only shops you might find open will be 'corner shops' and other smaller shops.
Chris