Lying is institutionalized long before Brexit. That's why the British is called "Perfidious Albion".
Look at how Jean-Jacques Rousseau said in 1762: "The people of England regards itself as free, but it is grossly mis- taken; it is free only during the election of members of parliament. As soon as they are elected, slavery overtakes it, and it is nothing.The use it makes of the short moments of liberty it enjoys shows indeed that it deserves to lose them."
"The Russians, a Cambridge don noted, ‘consider the English as a mercenary nation’ and one of their princes publicly declared that ‘in England there is not an individual, patriot, or placeman, who is not saleable to the highest bidder’."
Citing from "Cultures Differ Differently" by SN Balagangadhara, Routledge, 2022.