When the artists entered the museum, their works were already neatly packed and waiting for them. They spent several minutes unwrapping them to hold them up for waiting photographers.

The museum said it had removed 29 works, a third of those on display. They were replaced with signs reading, “This artwork was removed at the request of the lender who has objected to a private event by an aerospace and defense company that was held at the Design Museum.”

Cultural institutions are regularly the target of protests in Britain if they accept sponsorship or funding from companies seen as unethical. Tate and the British Museum have been targeted for exhibitions sponsored by the oil company BP. In March, the defense contractor BAE Systems withdrew its sponsorship from an arts festival, the Great Exhibition of the North, after several musicians pulled out. In the United States, protests have been seen recently at museums that have taken money from members of the Sackler family whom protesters link to the opioid crisis.

But it is rare for artists to withdraw their work from an exhibition. “I’ve been working in the sector for 20 years and I’ve never had this happen to me,” Alice Black, one of the Design Museum’s directors, said in a telephone interview.