The government said it will deport the migrants to Rwanda within two weeks on 14 June.
The Ministry of the Interior said it had begun issuing official notifications of deportation of migrants as the “final administrative step” within its framework Partnership with the East African country.
The Minister of the Interior said that there will still be attempts to postpone the process.
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Priti Patel said: “Our world-leading partnership with Rwanda is an essential part of our strategy to fix the broken asylum system and break the vicious business model of people smugglers.
“Today’s announcement is another crucial step towards delivering that partnership, and while we know that attempts will now be made to thwart the process and delay removals, I will not be deterred and will remain fully committed to delivering what the British public has come to expect.”
The Interior Ministry said an initial group of migrants had started receiving official letters telling them they would be sent to Rwanda to “rebuild their lives in safety”.
She said the policy was designed to break people-smuggling networks and stem the flow of migrants through the canal.
The Interior Ministry did not say how many asylum seekers would be on the first deportation flight to Rwanda.
It said earlier this month that it had begun issuing “notifications of intent” to some individuals informing them that they were “in transportation.”
She said officials were working to ensure individuals had “appropriate support” before leaving.
The government said those sent to Rwanda will receive support, including up to five years of training to help with integration, residency and health care.
Read more:
Why are migrants being sent to Rwanda and how will it work?
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The plan, announced in April, drew criticism from MPs inside and outside the Conservative Party as well as from many charities.
UN officials said the move violated the International Refugee Convention.
Last year, more than 28,000 migrants and refugees from continental Europe crossed into the UK, mostly in small boats.