You absolutely can just leave! Now, lets say the five times larger economy doesn't accept your unilateral trade position, who just happens to be by far your la

You absolutely can just leave! Now, lets say the five times larger economy doesn't accept your unilateral trade position, who just happens to be by far your largest and closest trading partner, what do you think happens then to your companies who are reliant on the EU market? Even if you don't work for such a company, what do you think would happen to your employer's clients? And if you work in the public sector, what do you think will happen to the tax revenue from those companies? More than 20% of the UK's GDP is made up of exports to the EU. What do you think will happen to the government that cost the country millions of jobs because of one stupid decision to appease populists come election year? That's why the government can't just leave because it would be extremely popular in the short term but within a few years bring about very dire consequences.