Employers can include bank holidays within your minimum annual leave entitlement of 5.6 weeks a year (28 days for a full time worker).
Following union campaigning, the UK Government agreed that it was unfair that mean employers counted bank holidays against the European minimum of four weeks' paid holiday.
These days, workers have a total holiday entitlement of four weeks (to meet the European minimum) plus eight days (the number of bank holidays enjoyed in most of the UK).
However, there is no legal right to take bank holidays off work, because many people (for example in the emergency services) have always had to work on bank holidays. What it does mean is that everyone will get four weeks plus either bank holidays or time off in lieu for bank holidays they have to work.
Of course, many people get better than the legal minimum, and it is quite common for people to be guaranteed all bank holidays off work in their contracts of employment.