The top EU figure said it was up to the next generation to “fix” the mistakes made by British politicians on Brexit in surprise remarks.
Ms Von der Leyen also suggested the UK was on a clear “direction of travel” towards re-joining the bloc in future, amid growing frustration among voters with Brexit’s impact.
Asked if Britain could ever rejoin, she told Politico: “I must say, I keep telling my children: ‘You have to fix it. We goofed it up, you have to fix it.’”
Ms Von der Leyen added: “So I think here too, the direction of travel – my personal opinion – is clear.”
The Brussels chief also described the Windsor Agreement she struck with Rishi Sunk on Northern Ireland as “a new beginning for old friends”.
No 10 immediately rejected the idea of reversing or “fixing” Brexit in response to Ms Von der Leyen’s provocative remarks.
Mr Sunak’s official spokesman said Brexit “freedoms” were allowing the UK to diverge from Brussels on immigration, animal welfare and medicine procurement.
“We are focusing on delivering Brexit,” he told reporters. “We are focusing on the benefits and opportunities Brexit can bring.”
Ursula von der Leyen and Rishi Sunak agreed post-Brexit deal on Northern Ireland earlier this year— (PA)
Although polls have shown support for rejoining the EU gradually growing over the last year, neither Labour nor the Liberal Democrats is promising to reverse Brexit.
Sir Keir Starmer’s party has promised a closer relationship with the bloc, but has ruled out rejoining the single market or customs union or any deal to bring back the free movement of people.
It comes as former home secretary Priti Patel said Mr Sunak needs to act on the “tentacles of EU control” which remain in place over Northern Ireland.
As the Sunak government remains in long-running talks with the DUP over Unionist concerns on post-Brexit trading arrangements, Dame Priti said she voted against the Windsor Framework because it “posed a risk to the integrity” of the UK.
Ms Von der Leyen’s surprise comments come as Mr Sunak’s new foreign secretary David Cameron is in Brussels to discuss Ukraine and other defence issues.
Foreign secretary David Cameron in Brussels on Wednesday— (Getty)
But Lord Cameron is expected to meet with European Commission vice-president Maros Sefcovic. The foreign secretary is reportedly keen to discuss the issue of post-Brexit tariffs set to be imposed on the automobile industry and coming into force in January.
Mr Sunak’s government is pushing the Commission to agree to delay the costly new “rules of origin” set to damage the electric vehicle (EV) market due to come in at the start of 2024 as part of Boris Johnson’s trade deal.
The new foreign secretary and former PM is also close to agreeing a post-Brexit deal with Spain to resolve the long-running row over arrangements for Gibraltar.
Spanish foreign minister Jose Manuel Albares revealed on Tuesday that he had been in crunch talks with Lord Cameron on a deal to avoid a hard border between Gibraltar and Spain.
A spokesperson for the Foreign Office said Lord Cameron had underlined the UK’s desire to get “a UK-EU treaty on Gibraltar as soon as possible” during his discussion with Mr Albares.
The Spanish minister suggested the outline of a deal was now in place for a “zone of shared prosperity” in the Spanish area next to the British territory to ease the flow of people and goods.