“I want to have my things in a public space and I want them to be seen. But I also want my children to be free to sell the works when they need to,” said Mayen Beckmann, the granddaughter of Max Beckmann, a leading 20th century German painter. She said she is considering whether to withdraw drawings on loan to the Leipzig Museum of Fine Arts.

Other collectors, she added, are starting to move their art to the free port of Luxembourg, where they can store it while the political process unfolds.

Like Mr. Baselitz, the German artists Günther Uecker and Gerhard Richter are considering whether to call in loans. In an interview this week with Dresdner Morgenpost, Mr. Richter said, “No one has the right to tell me what I do with my images.”

Both Mr. Richter and Mr. Baselitz have forged close relationships with the Staatliche Kunstsammlungen Dresden, a state art museum that includes the Albertinum. Since 2006, it has maintained Mr. Richter’s archive as a research institution, working closely with the artist and his Cologne studio.

In 2010, it created a special room at the Albertinum devoted to works chosen by Mr. Baselitz, 77, an influential postwar painter whose art often explores the pain of growing up in Nazi Germany. Among them were his portraits of Elke and Franz Dahlem, which are hung upside down.

Hartwig Fischer, the director of the state museum, said it came as a shock when Mr. Baselitz called to say he was withdrawing his loans.

“This is his gesture to comment on what is happening with the legislation,” Mr. Fischer said. “We will talk about possibilities in the near future, but for now the decision is definite and the works are leaving. That is very tough. I’m very sad about this.”