I have reached the end of my 39 weeks maternity and decided not to return to work. I received my P45 and have not been paid my outstanding holiday when I contacted my boss he admits I am owed holiday but claims I am only due a daily rate of my salary minus the maternity pay I have received, not just the holiday days at my full salary. I spoke to ACAS yesterday to confirm I am entitled to holiday pay and they said it should be at full salary, but is he right to deduct my SMP from this?