Home Office warned by MPs over "very leaky" system designed to prevent new Covid cases being imported.
The home secretary has claimed she wanted tougher measures to control coronavirus back in March.
Anyone who flouts the rules faces a hefty fine – though there are exemptions.
Charity Detention Action has sent a legal letter to the home secretary over the holding of unaccompanied children at a Border Force facility.
His comments came after Croatia and Austria were dropped from the UK's list of safe travel corridors.
There are concerns young girls may be among the unaccompanied children yet to be placed in care after Kent council reached capacity.
During today's daily coronavirus briefing, Priti Patel said overall crime has decreased during lockdown but warned criminals exploiting situation that law enforcement is “onto you”.
The first confirmed cases of the deadly virus were reported in Europe on Friday.
Expectant mother was on a sinking boat near Dunkirk as dangerous crossings surge.
The imminent closure of refugee camps in France may be driving a new wave of refugees.