Is it permissible for a guardian (wali al-amr) to marry his daughter to a man while she is engaged to another, and that other man still desires her?

If a woman is engaged but the marriage contract has not yet been concluded, it is permissible for her or her guardian to annul the engagement for a valid reason (maslaha). It is disliked to do so without a valid reason, due to the breaking of a promise, but it is not forbidden. Her marriage to a second suitor is valid. It is permissible for the guardian to withdraw their acceptance if they see a benefit for the fiancée, and it is permissible for the fiancée to withdraw if she dislikes the suitor. According to the Maliki school, annulling an engagement is not forbidden unless it is for the purpose of becoming engaged to another person. It is forbidden for a Muslim to propose to a woman who has already received a proposal and explicitly accepted it.