LONDON — The most recent YouGov poll, conducted one year from the date in 2019 when the UK officially leaves the European Union, shows that a majority of British people now regret voting for Brexit.

The vote to leave the EU was ...

Right: 42%

Wrong: 45%

Poll published March 29.

What changed since the 2016 EU Referendum? An avalanche of detail on exactly how the exit from the EU is going to work — much of which suggests Britain will be worse off outside the EU. The government's own economic analysis, for instance, shows Britain will be a poorer place under every possible Brexit scenario.

Those who believe Brexit was "wrong" have been in the majority since late 2017, according to this tracking chart from Pantheon Macroeconomics: