Shabana Mahmood has pledged to step up the number of migrants being returned to France, despite just 42 returning so far under the "one-in-one-out" scheme.
The Home Secretary said she will do "whatever it takes" to secure Britain's borders after a record 16 migrants were returned to France last week.
More flights are expected to take place within the coming days.
Ms Mahmood said: "For many years, illegal migrants entered our country with no consequence.
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"This is the largest return flight under our historic deal with the French.
"And it sends a warning to those considering entering this country illegally: if you come here by small boat, you can be sent back.
"This is just the beginning – I will scale up these removals to France.
"And I will do whatever it takes to secure our borders."
A total of 42 migrants have so far been returned under Britain's 'one-in-one-out' deal with France
|REUTERS
Under the "one-in-one-out" treaty, which came into force this summer, anyone entering the UK on a small boat can be immediately detained and returned to France.
An equal number of migrants will then be eligible to come to Britain through a new route, subject to security checks.
It is understood that the number of migrants arriving in the UK under the deal currently stands at 23.
Shadow Justice Secretary Robert Jenrick yesterday slammed the "pathetic" returns deal.
He wrote to X: "490 illegal migrants broke in this week. 16 out, another 16 in.
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Shabana Mahmood said she will do 'whatever it takes' to secure Britain's borders
|PA
"This swapsies with the French is pathetic. Each one is estimated to cost us £400,000 while here.
"So that’s a meagre £196million sunk this past week alone. Remember this as taxes rise."
On Saturday, 369 migrants crossed the Channel in seven boats, bringing the number for the year so far to 36,734 - 82 short of the entire total last year.
Border security chief Martin Hewitt this week told MPs that the number of arrivals by small boat to the UK is "frustrating" but insisted work to stop the smuggling route was "always going to take time".
Under the returns deal, anyone entering the UK on a small boat can be immediately detained and returned to France
|PA
Ms Mahmood met with counterparts from the Western Balkans and other European allies in central London last week to discuss new actions to drive down illegal immigration.
International policing efforts are attempting to crack down on smuggling gangs who have plotted trafficking routes through the region.
This week, Sir Keir Starmer will host a leaders’ summit with Western Balkan countries to agree further measures to bring down the number of migrants arriving illegally to Britain.
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