And Britain is rife with uncontrolled immigration?
Let's see the latest stats in June 2023 were that 1.2 million people entered the UK for that year (they seem to go from June to June for some reason), 508,000 left the uk, so total net migration was 672,000.
Now illegal migration was 52,530 with 40,386 coming via small boats. That's less than 10% of net migration and less than 5% of total migration. For the small boats 36,169 was asylum applicants which is completely different to a migrant (unless your the conservatives who can't tell the difference). So in terms of small boat migrants, we have number of migrants at less than 1% for both total and net migration.
www.gov.uk
I don't really see this as an uncontrolled influx.
Further, it is impossible to claim asylum outside the UK and it is impossible to for asylum seekers to get a visa to come to the UK. Therefore the UK actually encourages small boat crossings and supports these criminal gangs by making it extremely difficult for asylum seekers to arrive.
If you want to stay in the UK because you are unable to live safely in your country for fear of persecution, you may be eligible to claim asylum.
newcastle-immigrationlawyer.co.uk
As for foreign powers looking to destabilise a country, ignoring the fact that our own government is doing a pretty good job of that on it's own, where are we going to get a huge sudden influx of refugees from? We're not near any active war zone and the UK takes very small numbers of refugees compared to other countries around the world. It's not really relevant to the UK.
I'm sure people will disagree, but for me the issue of immigration in the UK is nothing more than political scapegoating to try and hide the fact that the country has been run down by Tory incompetence. It's not a problem now and it's unlikely to be anytime in the near future.