A lot of people are asking how Paddington Bear would be accepted by the UK's immigration system. I see what they are getting at, but there is one big problem. Paddington is a bear. As such he doesn't get to immigrate, and is governed by a whole different set of bureaucracy.
First of all, Paddington appears to be a spectacled bear (Tremarctos ornatus) from Peru, or at least some sort of being which shares a common ancestor with that animal. He may be able to walk and wear raincoats, but a bear is still a bear in wildlife law. Furthermore he a member of an endangered species listed on CITES Appendix I. That makes it illegal to transport or possess him without a license. I suspect that the Brown family have no such permission.
Okay, purists may quibble that CITES didn't exist in 1958 when the original books came out, but as far as the remake goes, they're in trouble, as are the airlines and boats which took him to Britain.
Of course CITES is often not enforced (that's why there is still a huge illegal wildlife trade) and does not apply to species which spread themselves naturally. So might he sneak in? The trouble is at some point he will be seen, and come to the attention of the authorities. The question then will be - is Paddington's arrival in Britain merely the result of changes in the species natural range?
Currently natural range is poorly defined, but the new infrastructure bill going through Parliament would see it fall somewhere into two categories - the historic range of a species, and a species which arrives by itself naturally, with no human help.
The wild boar which live in the UK are in their former natural range (they were once found right across Britain until a few hundred years ago), but because the government judges them to be here by unnatural means (they likely escaped from breeding centres), they are not considered to be native. The chances of a bear from South America which arrived by boat and train, carrying a suitcase and being fed sandwiches being judged to be within its natural range are slim at best.
Sadly, it seems likely that as a non-native and potentially invasive species, Paddington would be more likely to have a 'species control order' placed on him. At best he would be trapped and placed in the zoo, at worst hired marksmen would be able to force their way into the Brown property and shoot him.
The truth is that our government takes such a narrow view of wildlife that even native species which have lived in this country for decades, which bring many benefits and which form an essential and historical part of our natural fauna, have a hard time being left alone. A bear from Peru wouldn't have a chance.