Separations and effects on kids

My partner and I are breaking up and I don’t want him picking the kids up without my permission. Is there anything I can do?
Schools are very used to this situation. Often, break ups will be unpleasant for all of the parties concerned and clearly the school’s overriding concern is to protect the emotional and physical wellbeing of the child – it certainly cannot ‘take sides’. In situations like this, the school will invariably encourage the adults to reach agreement so that the school is not being used as some sort of a pawn in the game of break-up chess! Bottom line, unless there is actually a court order in place that states anything to the contrary, both parents will have legal, parental responsibility and a school cannot do anything other than apply fairness in the eys of the law in such a situation.