Is the presence of the absent and neglectful father required for the validity of the marriage contract, and is the contract considered void if the guardian is the maternal uncle?

Guardianship (wilayah) is a condition for the validity of marriage. The father is the most rightful guardian to give a woman in marriage. If the father is competent to be a guardian and is not preventing the marriage without just cause (a'ḍil), then no one else can give her in marriage except with his permission. The father may delegate someone else, such as the girl's maternal uncle, to complete the marriage contract if he (the father) is far away. The father's shortcomings in fulfilling his duties towards his children do not negate his guardianship over them. The maternal uncle has no guardianship over his sister's daughter except with her father's permission; otherwise, the marriage would be invalid. Children must honor their father and treat him well, even if he falls short in his duties towards them.