The vote to leave the European Union (EU) is leaving a lasting impression on the shape and size of Whitehall. There are new departments, new priorities and thousands of new civil servants.

These changes don’t come without cost. After years of strict controls on departmental budgets, the Chancellor is loosening the purse strings. In the 2017 Autumn Budget, he announced that an extra £250 million (m) had been shared among departments in 2017/18, and a further £3 billion (bn) has been set aside to fund Brexit over the next two years.

This IfG Insight paper looks at six of the government departments most affected by Brexit in order to understand where this money is going and what else Whitehall is spending on leaving the EU. It shows that the Treasury numbers only tell part of the story.