I think this question has been asked before but I don’t recall you answering it ^ , so forgive me if you have.What would you like Labour to be doing to stop the boats? ^
If you really want to expend the energy in a debate like this (who knows, you may need the benefits of exercise you can only gain from pointless activities) the be aware it really is a Sisyphean task. You'll get to within an inch of sense and then from nowhere an extra twiddle will appear.
It's much easier and efficient to start with the assumption you will never get a straight answer. Then at least your expectations aren't too high.
Fans of Brexit will remember similar exercises where some posters after accepting they were wrong, but would still have voted to Leave, finally admitted that whatever the reality - even if being in the EU meant free goats and a months holiday in Scarborough - they just didn't want foreigners in the UK. We knew this because every single discussion descended into quoting immigration figures.
You know what ? If the schools teach, if the hospitals teach, if children don't go hungry, if every subject can feel secure, safe and valued ... if we can all work to that than I give no fucks how many people may - or may not - "come over here". And that sentiment has been honed over decades of learning how we are still effectively ruled by a bunch of Norman invaders who - unlike todays immigrants - most definitely didn't pass a citizenship test.
The biggest irony is (again, challenging my atheism) is that the single most effective way to deter immigration for all time would be if the people so vexed by it forced the UK to speak anything other than English.
Just hang a banner on the cliffs of Dover 欢迎来到英国 - that'd solve it.