Your employer may only refuse parental leave if they have reasonable grounds to believe you are not entitled to it. In this instance, they must notify you of the reasons for the proposed refusal, and you must be given the opportunity to make representations on your own behalf.
If you are eligible for your parental leave, your employer cannot refuse it.
However, they do have the discretion to postpone your leave, if granting the dates you’ve requested would have a “substantial adverse effect on the operation of the school.”
If your school wishes to postpone your parental leave, they must notify you of this with at least four weeks’ notice and agree new dates which fall within six months of the dates originally requested.
Parental leave can only be postponed once in respect of a particular child, or on two occasions if the postponement is due to seasonal variations in work.
If you have requested a period of parental leave which is more than six weeks in duration, the minimum which must be approved by your employer is six weeks.