TAMWORTH, England—Angus Dobson said he is prepared for the British economy to slump if it means breaking decisively with the European Union, an institution he views as distant, interfering and unaccountable to voters.
“For me, it was all about sovereignty,” said the 43-year-old biology teacher, referring to 2016’s Brexit referendum. “What we will gain by coming out of the EU long term is worth the economic downturn.”
Fifty-nine...