Claim: Trading with the EU under World Trade Organisation rules alone would cost the UK £45 billion in lost GDP.
Fact-check: How much would a hard Brexit cost? - Full Fact
Verdict: that's quoting the treasury's forecast incorrectly. £45 billion was the treasury's estimate for the cost to tax revenues after 15 years, rather than the size of the economy. it's not unorthodox to say that trading with the eu under terms set by the wto would be bad from an economic perspective. even so, no forecast is certain.
Organisation: Full Fact
Author: Richard Braham
Date published: 2017-02-10T00:00:00