while this is clearly good reason for Brits to hate Stalin, I sincerely doubt any significant portion of the general population is even aware of it. Your average Brit has heard of the purges, the terrors of Soviet communism and maybe about Soviet spies infiltrating the British government (Philby, Burgess, Maclean etc), but that's about it. practically no one has any awareness of our government's actions in the era after WW2

I think this is highly unlikely to be the explanation