On Tuesday, the Department of Home Affairs announced the revocation of Adetshina and her mother's South African identity and travel documents, citing their inability to validate the legitimacy of these documents.
Nevertheless, Adetshina arrived in Mexico on Wednesday with a Nigerian passport to compete in the pageant scheduled for November.
The petition, launched on Wednesday, quickly amassed over 500 signatures within a single day.
“As Progressive Forces of South Africa, we are writing this letter on behalf of everyone who stands for justice to plead with you Miss Universe as an organisation to reconsider the contestant Miss Nigeria Universe and, if possible, to cancel her entry,” the petition stated.
The petitioners contended that permitting her participation could undermine the integrity of the organization.
“Miss Universe is a known brand of class, integrity and fair competition. Miss Universe is known for granting a good platform to women from all walks of life to make a positive contribution to society while being the golden key to unlocking endless possibilities.
“We would hate to see the pageant losing its good image due to a contestant whose mother [allegedly stole] the identity of an innocent citizen. Not only did this contestant bring her own country into disrepute, but her participating in this iconic pageant would also bring Africa into disrepute.”
This is not the first instance of opposition faced by Adetshina. A similar petition was filed during her participation in the Miss South Africa contest, which ultimately led to her withdrawal. She later entered and secured the title of Miss Universe Nigeria, representing her father's homeland.