What is the effect of a breach of a covenant respecting custody of a child?

The breach of a covenant respecting custody contained in a separation agreement is, of course, a circumstance to be considered and weighed along with all other relevant circumstances, but the future welfare and happiness of the infant is always the final and paramount consideration upon which the decision should be reached. The decision of custody applications does not depend on whether or not there has been a breach of a covenant in a separation agreement. The effect of such a breach was referred to by Lord Simonds in McKee v. McKee, supra, where he said at p. 188: “The fact that the father had broken an agreement solemnly entered into was therefore a circumstance which the judge had to take into account and weigh in determining what was for the welfare of the child. * * * [it] was only one of many elements in the case.”