The government said it would deport migrants to Rwanda in two weeks’ time on June 14.
The Interior Ministry said it had begun issuing formal expulsion notices to migrants as the “final administrative step” in its association with the East African nation.
The interior minister said there would still be attempts to delay the process.
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Priti Patel said: “Our world-leading partnership with Rwanda is a key part of our strategy to review the broken asylum system and break the bad business model of human traffickers.
“Today’s announcement is another critical step in achieving this partnership, and while we know that attempts will now be made to thwart the process and delay the dismissals, I will not be deterred and will remain fully committed to delivering what the British public awaits “.
The Interior Ministry said a first group of migrants had begun receiving formal letters telling them they were being sent to Rwanda to “rebuild their lives safely”.
He said the policy is designed to break down human trafficking networks and curb the flow of migrants across the Canal.
The Interior Ministry did not say how many asylum seekers would be on the first deportation flight to Rwanda.
Earlier this month, he said he began issuing “notices of intent” to some people informing them that they were “in a position to relocate.”
He said officials are working to ensure people receive “proper support” before departure.
The government has said that those sent to Rwanda will receive support, including up to five years of training to help with integration, accommodation and health care.
Image: map of Rwanda
Read more: Why are migrants being sent to Rwanda and how will it work? Asylum seekers “willing to hide” to avoid Rwanda’s plan First vision inside the center that could house migrants from the Canal
The plan, announced in April, has drawn criticism from MPs inside and outside the Conservative Party, as well as from many charities.
UN officials have said the move would violate the International Refugee Convention.
Last year, more than 28,000 migrants and refugees crossed from mainland Europe to the UK, mostly in small boats.