Werner Hoyer admitted today the loss of the UK’s 16 percent stake in the bank, which makes loans at low rates for infrastructure projects, would be “painful”.
But he said that would be nothing compared to the financial “gap” coming the UK’s way after Brexit, branding it “the most terrible decision of 2016”.
He claimed funding by the EIB for projects in the UK is likely to disappear once it leaves the bloc.
Mr Hoyer said: “It will be felt in the UK. We will leave a gap.”
He claimed Britain has no comparable national financing bank and would lose annual investments of between £6.2billion and £7.9billion.
The banking chief pointed to infrastructure projects and wind farms in the North Sea as projects that would now suffer.
Despite his claims, Brexit is likely to be a huge blow to the bank.
The UK is one its largest shareholders, alongside France, Germany and Italy.
Currently, Britain has around £3.1billion in capital invested.
But, once equity, reserves and profits are factored in, that figure is thought to be closer to £9billion.
The EIB itself invested around £36billion in UK investment projects from 2011 to 2016.
It was revealed last October that the EIB could owe the UK billions for decades years after Brexit, provoking outrage.
Bank chief Alexander Stubb said the 16 percent stake would not be returned until 2054.
He said: “Everyone on both sides of the negotiating table agree that we have to pay back the €3.5billion, basically in cash, and that will happen over a long period, up until 2054, because that’s when the loans are amortised.”
However, under current treaty provisions only EU member states can join the EIB.
That means the EIB would keep Britain’s money for 35 years but would be unlikely to keep investing in the country.
(Additional reporting by Monika Pallenberg.)