[1][2] Elad Chakrina subsequently announced his intention to file an appeal to the Constitutional Council, alleging electoral fraud, claiming that results reported late in the evening from the commune of Bandraboua were "completely falsified".

[3] On 19 January 2018, the constitutional council annulled the election of Ramlati Ali on the basis of several complaints, triggering a by-election within the constituency.

Chakrina also claimed at least 40 proxy votes were irregularly cast in Bandraboua on 9 and 16 June 2017, and provided documents relating into a judicial investigation that had been opened to look into the matter.

Following the decision of the constitutional council, the only two remaining members of the La République En Marche group in the National Assembly representing overseas France are Olivier Serva are Stéphane Claireaux.

[8] Incumbent deputy Ramlati Ali, a 56-year-old former mayor of Pamandzi and head of the medicine, psychiatry and rehabilitation department at the Mayotte Hospital Centre (CHM) who joined La République En Marche!

[10] Due to the judicial affair, Ali did not receive the support of La République En Marche in the by-election,[11] and presented her candidacy without the backing of any party.

[12] Elad Chakrina, a 37-year-old lawyer and municipal councillor from Tsingoni,[9][13] contested the constituency once more under the banner of The Republicans (LR) after his successful appeal.

[8] During a three-day visit from 5 to 7 March, LR president Laurent Wauquiez denounced the "abandonment" of Mayotte by Macron,[14] saying that the department was "submerged by illegal immigration".

[24] Saïd Omar Oili, president of the association of mayors of Mayotte, announced the closure town halls in protest, and warned that the by-election might be threatened by the unrest.

[30] Although mayors requested the postponement of the by-election due to security concerns and the difficulty of campaigning,[31] the by-election ultimately went ahead, albeit with certain difficulties due to roadblocks, transport issues, padlocked polling stations, and landslides caused by tropical storm Eliakim, all of which caused delays to opening of polling stations in several communes.