Brexit to cost UK £72bn by 2021: Office for Budget Responsibility
The impact of Brexit will cause the UK economy £72bn in lost economic activity by 2021, according to the Office for Budget Responsibility's economic and fiscal outlook. This equates to GDP being 3.4% smaller in 2021 than originally estimated in March 2016, before the referendum took place.

The latest update of our forecasts was published on the 22 November 2017 in the November 2017 Economic and fiscal outlook. Read the overview.

In Chapter 2, we begin by looking at the main developments since our last forecast and the latest external forecasts for the UK economy. The latest outturns give us a starting point for our forecasts.

Chapter 3 sets out our forecasts for the economy over a five year horizon. We cover our assumptions regarding the UK’s exit from the EU, our latest forecast changes in light of recent developments and the effect of policies announced in the Budget.

Chapter 4 sets out our forecasts for receipts and public spending over a five year horizon. We also explain our loans and other financial transactions forecasts. All this, together with new policy decisions, builds the outlook for borrowing and debt.

In Chapter 5, we assess the Government against its fiscal targets. We examine whether the Government has a better than 50 per cent chance of meeting them on current policy. We also test the sensitivity of our fiscal forecasts in an alternative economic scenario.

Annex A covers the Autumn Budget 2017 policy decisions and Annex B explains the UK’s EU contributions in our spending forecasts.

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