Migrants who have crossed the English Channel are to be housed in military barracks while their asylum claims are processed.
Napier Barracks in Folkestone, Kent, will be a temporary home for around 400 people from next week.
It is understood the number will include migrants who crossed into the UK in small boats.
The accommodation is a former Army barracks and is part of the Shorncliffe Training Estate.
The leader of Folkestone and Hythe District Council and the chairman of Sandgate Parish Council have demanded the decision be reversed.
Folkestone and Hythe MP Damian Collins has also said he "cannot support" the decision.
In a joint letter to Home Secretary Priti Patel, they said: "We have great concerns about the impact this large open camp will have on the welfare of the local residential community and also those people in the asylum system who will be placed at the barracks itself."
Folkestone and Hythe District Council has criticised the plan for a "lack of consultation" and "exceptionally poor communication", adding: "We are quite sure that members of the community will have many questions, and we are seeking clarification as a matter of urgency."
Another barracks, at Penally Camp in Pembrokeshire, Wales, is also being considered for use by the Home Office.
The news comes after at least 168 people crossed to the UK on small boats on Monday.
A Government spokesperson said it is working with its partners and a number of departments to "secure further accommodation", adding the Ministry of Defence (MOD) has offered "use of some of its sites".
The spokesperson also said the Government tries to ensure "vulnerable asylum seekers, who would otherwise be destitute, have suitable accommodation while their claims are processed".
Any training at the two sites will be relocated to alternative sites or rescheduled, so there will no military personnel on site if and when they are used by the Home Office, according to the PA news agency.
Meanwhile, immigration minister Chris Philp announced that 14 people who had crossed the Channel to Britain had been deported on Tuesday.
He said on Twitter that they had been removed to European countries following "last minute vexatious legal claims".
It comes after a Watchkeeper drone, previously used in Afghanistan, carried out its first reconnaissance sortie of the English Channel after being deployed to monitor migrant boats.
An RAF Atlas has also recently been deployed to support Border Force operations in the Channel.
Cover image: Napier Barracks in Folkestone, Kent, where migrants will be housed while their asylum claims are processed (Picture: PA).