Pale Rider
Veteran
They beach their boat at Dungeness and are picked up by Border Force.
They claim Asylum.
If they're found to have refugee status then they'll get leave to remain.
It they're not refugees but what you term economic migrants then where do they go?
Brexit makes it more difficult to return them to the EU as the Dublin Convention about first place of safety (though actually not that simple in practice) no longer applies.
A further host of reasons, some of which are Brexit related may make it difficult to return them to their 'home' country.
PS - did you ever see the RNLI fly on the wall thing I recommended about pulling migrants from the sea?
Do you honestly think that upon our leaving the EU, thousands of economic migrants thought 'time I got paddling'?
For whatever reason our country - which you and many others on here do nothing other than slag off - is extremely attractive to those crossing the channel.
It was before Brexit, and it still is afterwards, thus Brexit is largely irrelevant to economic migrants seeking to enter this country illegally,