I read another thread about this recently.... It depends what your employers holiday policy is.... i.e. do you have to use your annual holiday entitlement for bank holidays, or are you 'given' bank holidays free?
For example, my husband runs a company & gives all his staff 30 days holiday per year. However, those 30 days HAVE to include all bank holidays too i.e. staff are given 30days holiday per year, then taking into account all the bank holidays during the year, which totals about 8 I believe, they are left with 22 days holiday to take whenever they wish.
I do all the finances for my husbands business, & when I joined I thought this holiday policy was MEGA unfair, and also not allowed. However, he had taken legal HR advice and proved to me that this is perfectly allowable.
So, if your company has a policy whereby you are given a certain number of holidays per year but you have to use some of those for the bank hols, then I dont think you can argue you are owed the bank hols during mat leave. If, on the other hand, you usually get all the bank hols off for 'free' so to speak, then you might have an argument to make with your employer.
Does your company give you any enhanced mat benefits on top of the SMP you are entitled to?