Written question asked by Bernard Jenkin (Conservative) on Wednesday, 20 May 2026, in the House of Commons. It was due for an answer on Monday, 1 June 2026 (named day). It was answered by Torsten Bell (Labour) on Monday, 1 June 2026 on behalf of the Treasury.

Economic Growth: Brexit

Question: To ask the Chancellor of the Exchequer, what assessment she has made of the impact of leaving the EU on the underlying growth rate of the UK economy; and what recent analysis her Department has undertaken on that issue.

Answer: The Office for Budget Responsibility (OBR) is the government’s official forecaster. The OBR has included assessments of the economic impacts of leaving the EU in its forecasts since 2016. In March 2020 the OBR estimated that, as a result of the deal negotiated by the then government, GDP will be 4% lower in the long run than it would have been had the UK not withdrawn from the EU. As of the Spring Forecast 2026, these assumptions are unchanged from its previous assessment.

Secondary information