Sir Keir Starmer, the Labour leader, will meet Olaf Scholz, the German chancellor, in Berlin on Friday to discuss Brexit and the war in Ukraine.
It will be the first time the two have met since Mr Scholz became chancellor last year.
Sir Keir, on a two-day trip to Germany with David Lammy, the shadow foreign secretary, has also held meetings with members of the Social Democratic Party government.
The pair arrived at the German Chancellery on Thursday to meet Wolfgang Schmidt, Germany’s federal minister for special affairs, head of the chancellery and commissioner for the Federal Intelligence Service.
Sir Keir and Mr Lammy later visited a business start-up hub, meeting entrepreneurs and the chief executives of leading business support groups.
They are set to attend meetings with Mr Scholz and Sigmar Gabriel, the former German minister of foreign affairs, on Friday.
Sir Keir is expected to tell Mr Scholz that Labour is ready to form a government and has a plan to ensure that Britain and Germany can work together to help boost economic growth and stand united against Russian aggression, Labour said.
The leader and Mr Lammy are also aiming to find out what Britain can learn from the best economic models around the world, and how a future Labour government could work with other European nations to navigate the post-Brexit world.
On Thursday, they will visit the Memorial to the Murdered Jews of Europe to remember the millions killed in the Holocaust.
Last month, Peter Mandelson, the Labour grandee, said Labour could achieve a “governing coalition” of social democrats, liberals and greens at the next election by emulating Mr Scholz. He said Labour could achieve victory without a formal pact with other parties.
Lord Mandelson said that, like Mr Sholz, Sir Keir was an “unflashy performer” but the chancellor could be seen as “a template” for victory at the next general election.