The borders can't be closed forever, or at all 100%, we are not a self sufficient country, so sooner or later new variants will either occur here or come here, it's what viruses do, they mutate and they don't care about borders.
Creating an immune response by vaccination is the only way to go. In that case, even if a new variant does occur our bodies are ahead of the game. Covid isn't going anywhere, we are just finding ways of making it less lethal.
The lockdown needs to follow the path set out and it needs to happen, if it doesn't people will lift it themselves by default and all bets will be off. It's a fine line of working with what needs to happens vs what will happen if it does/doesn't.
I think sometimes it's good to stand back and stop seeing Europe/other countries as some kind of threat, either as a gateway for disease, or in the political shenanigans that abound. The virus is the threat, fight the virus.
Last weekend, in Rutland, the first statue in Britain of the late Elizabeth II was unveiled.