Given that by international agreement the UK cannot refuse entry to anyone who claims asylum, what do you want them to do? Require visas like they will for all South Africans?

As the problem is originating in Canada, surely Canada should be the country dealing with the problem as they are clearly allowing people into Canada who shouldn't be there

Given that the airline carrying with asylum seeker will get heavily fined, this seems to be a policy of the airline to cut that risk - not the UK government - though how it helps I don't understand.