Authorities in Mayotte are expected to launch Operation Wuambushu ("Take Back") next week to remove illegal migrants who have settled in slums on the island "The Comoros do not intend to welcome people expelled as part of the operation planned by the French government in Mayotte," government spokesman Houmed Msaidie told AFP MORONI, Comoros: The Indian Ocean archipelago of the Comoros warned Friday it would not accept migrants expelled from the neighbouring French island of Mayotte in a looming operation that has triggered a diplomatic spat. Authorities in Mayotte are expected to launch Operation Wuambushu ("Take Back") next week to remove illegal migrants who have settled in slums on the island. Those without papers are to be sent back to the Comoran island of Anjouan, 70 kilometres (45 miles) away. "The Comoros do not intend to welcome people expelled as part of the operation planned by the French government in Mayotte," government spokesman Houmed Msaidie told AFP. Msaidie said the planned action went against "the spirit and the letter" of agreements between the two countries. Around half of Mayotte"s roughly 350,000 population is estimated to be foreign, most of them Comoran. On Friday, French Interior Minister Gerald Darmanin confirmed the operation would take place but declined to give a date for its start. Some 1,800 police officers were already in Mayotte to deal with "criminal gangs," he said. In total, around 2,500 personnel from law enforcement, health and judicial services have been mobilised, according to a source familiar with the matter. Moroni earlier urged Paris to drop the operation -- plans for which were first reported by the French satirical weekly Le Canard enchaine in February. Anjouan governor Anissi Chamsidine said the island was unable to "cope with the violence created from Mayotte by the French state." Comoros" President, Azali Assoumani told AFP last week he hoped the plan would be abandoned, but acknowledged he lacked "the means to stop the operation through force." Mayotte and the three islands of the present-day Comoros were French territories until 1975. Following a referendum on independence, Grande Comore, Moheli and Anjouan islands declared themselves to be a separate country, the Union of the Comoros. But Mayotte voted to remain a French overseas territory and later became a French department -- a status rejected by the Comoros, which continues to claim the island. It is France"s poorest department with around 80 percent of the population living beneath the poverty line and high levels of social delinquency. But it also benefits from French infrastructure support and welfare, and this has encouraged an influx from the Comoros, with many migrants attempting the hazardous crossing on rickety boats used by smugglers. In 2019, France stepped up efforts to stem the flow, strengthening sea patrols that are supported by air surveillance. Earlier this month, civil society groups in Comoros warned that Operation Wuambushu -- which has been approved by French President Emmanuel Macron -- was a "massacre waiting to happen" and urged international organisations to intervene. Intense negotiations between Moroni and Paris have taken place in recent weeks, raising the possibility of a last-minute agreement.