This week, the government deported two small boat migrants to France as part of the one in, one out deal.
But its status as a deterrent is under question - as people are still crossing the Channel in small boats.
Having set off this morning, dozens of people have been collected from the waterway by Border Force and brough ashore for processing.
If the government gets its way, most of them will be returned to France.
An 'immediate deterrence'
Deputy prime minister David Lammy told broadcasters earlier that "it has been very important to increase the numbers of people that we are returning" to where they're from - although this is a reference to other deportations like criminals.
He claims the "pilot" deal with France is a "milestone" as it sends an "immediate deterrence".
Lammy says that the government hopes more people will be sent abroad in the coming months and years.
Asked if the UK would send in the military as Donald Trump suggested to stop people crossing the Channel, Lammy said: "We've got amazing border guard.
"The Navy do play a role in providing some of the support and logistics that you recognise and need, in the Channel.
"And I'm also very pleased that Ministry of Defence colleagues are working closely with the Home Office as we look harder, at a new group of accommodation, on some of those sites where we can accommodate, those who are waiting for their asylum applications."