x     A long-term scenario of zero net migration would reduce the United Kingdom's economy by 15% by 2060 and limit GDP growth to an annual average of 0.9%, according to a report published on Wednesday by consultancy Oxford Economics. The study, which examines the impact of migration on British GDP and public finances, comes amid intense political polarisation over immigration controls. The report sets out two scenarios considered “plausible” based on the consultancy's global economic model.