“I personally hope and wish that Britain will stay part and parcel of the European Union,” Merkel said at a press conference after talks with NATO secretary-general Jens Stoltenberg in Berlin.
It's one of the clearest statements Merkel has made on the question of Britain's membership. Until now she has usually brushed off questions by saying that it was a choice for the British people.
But on Thursday she praised the UK as a force for positive change in the EU.
“We work well together with the United Kingdom, particularly perhaps when we talk about new rules for the European Union,” the Chancellor said.
German leaders often express their appreciation for Britain as a key ally for the Federal Republic and other northern European nations in battles over the future direction of the EU.
Among top politicians in Berlin and Brussels, the fear is that without Britain, countries inclined towards free trade and strict fiscal rules like Germany, the Netherlands and Finland could find themselves outvoted by a 'Club Med' of France, Italy, Spain and other southern nations.
Hello from the outside
Merkel also made reference to the fact that if Britain were to leave and then wish to retain access to the EU's single market, it would have to accept EU standards with no say in their drafting – a situation Norway finds itself in today.
“You can much better have an influence on the debate when you sit at the bargaining table and you can give input,” she said.
“It would not only be in our interest, but also in the interests of Britain, if it can bring its whole political weight to the negotiating table.”
What's more, leaving the EU would cost the UK important weight to throw around in trade negotiations with third countries, Merkel went on.
“One nation by itself will never be able to achieve such good results” as the EU bloc of 28 nations and roughly 500 million people, the Chancellor said.
It's uncertain how much influence on the referendum debate in Britain itself Merkel's intervention will have.
Comments from other world leaders including US President Barack Obama have been slammed by Brexit campaigners as unwelcome interference in British affairs.
Merkel's personal opinion could be even more unwelcome, as Leave campaigners have long painted her as a despot who bullies other EU nations into accepting unfair conditions that favour Germany.
Brexiters would also point out that Germany has a lot to lose from the economic fallout if Britain quits the EU – meaning that the public could see Merkel's comments as self-interested.
But with recent polls indicating the Leave campaign pulling ahead, the Chancellor may have decided that the risk was worth it.
A Guardian/ICM poll on Tuesday showed a 52-48 split in favour of leaving.
“Merkel answered very comprehensively about why she's against Brexit. She obviously wants to send a signal. The latest polls in the UK are having their effect,” ZDF TV journalist Thomas Walde tweeted.
Merkel antwortet seeeeehr ausführlich, warum sie gegen einen #Brexit ist. Will offenbar Signal setzen. Jüngste Umfragen in GB zeigen Wirkung
— ThomasWalde (@ThomasWalde) 2. Juni 2016
The Financial Times rolling average of polls showed the Remain side on 46 percent and Leave on 43 percent on Thursday afternoon.
SEE ALSO: Out means out, Germany warns Brexit camp