The German chancellor has followed Emmanuel Macron’s lead by criticising Brexit in front of Keir Starmer.
Friedrich Merz labelled Brexit “deplorable” after he signed the first UK-Germany treaty since the Second World War.
His comments come after the French president said Britain’s exit from the European Union was “deeply regrettable” on his state visit last week.
Merz said the new treaty with Sir Keir comes under “major challenges of our time,” citing Brexit and the Russian invasion for “shaking the European security architecture”.
“It is under these conditions that we aim to secure the freedom, prosperity of the people of both our countries,” he said.
“That is really the agreement we have both signed up to.”
Speaking at the Guildhall, Macron also criticised Brexit, saying: “I am very respectful for the voice of the people and the choice your country made nine years ago, and I’m lucid about the solemnity of the state visit being the first one of a European head of state post-Brexit.
“But I have to say the European Union was stronger with you and you were stronger with the European Union,” he added to a round of applause.”
He added the UK and France had to “work together” despite Brexit saying: “We have to take our responsibilities together, we have to clearly decide to choose our future, to write our future together.”
Commenting on the new UK-Germany deal, the PM said the “scale of the challenges” Europe faces has brought the two countries together.
He argued: “We intend to meet them head on. But we also see the scale of the opportunities, so we have a shared resolve to deliver security for working people.”
“We’re also working together on illegal migration,” he concluded. “It’s a clear sign that we mean business – we are coming after the illegal gangs in every way that we can.”