Is it permissible for the son to be the guardian (wali) in the marriage contract if the father is present, whether the father agrees to the marriage or not?

The guardianship of marriage belongs to the father, then the grandfather, then the sons, then the brothers. It is not permissible for a son to arrange his mother's marriage if her father is present, except with his permission, or if the father is absent or preventing her marriage (عاضلاً). In this case, it is valid for the son to arrange his mother's marriage. However, if the son arranges her marriage in the presence of the father without his permission or presence, the contract is not valid and must be redone.