highlights_snippet: Britain must choose between a £56billion-a-year hit or continuing to offer open borders to European migrants if Britain chooses to leave the EU, a think-tank has warned.
highlights_snippet: Open Europe said an exit would lead to a dent in national income of 2.23 per cent by 2030, with export tariffs of up to 10 per cent.
highlights_snippet: The only way to avoid this would be a free trade deal, allowing free movement of workers.