Staff removing the British flag from the European Council building in Brussels last Friday, the same day that the bill was delivered

Britain faces a European Union budget surcharge of £1.1 billion even after Brexit because of an annual adjustment to national contributions.

By “pure coincidence” the bill was delivered last Friday, hours before Eurosceptics celebrated leaving the bloc. Under the terms of the withdrawal treaty, Britain is legally obliged to pay the adjusted sum.

“This is a routine annual budgetary exercise and we will stick with the rules,” a spokesman for the European Commission said. “The UK has been informed of what needs to be done. Member states have the obligation to pay their contribution to the budget and there are procedures to make sure they do. [The UK] was still a member on that day and so then those obligations continue.”

The recalculation, using