Wolfgang Tillmans’ anti-Brexit poster campaign at Photo London 2016. Courtesy of Lorena Muñoz-Alonso.

In a climate of contracting auction sales, the last thing the art market needs is more uncertainty. But with the Brexit referendum approaching, more uncertainty is precisely what is characterizing the upcoming London auctions, which take place at Sotheby’s and Christie’s at the end of the month.

According to Bloomberg, all eyes are on the referendum, as British residents decide whether to stay in or leave the European Union. Sellers are holding onto their prized works, and buyers are hoping for bargains at Sotheby’s and Christie’s Impressionist and modern art evening sales on June 21, and June 22, respectively, as well as the two auction houses’ modern contemporary art evening auctions on June 28 and June 29.

Judging by the pre-sale estimates, Sotheby’s and Christie’s expect a 20 percent drop in sales volume compared to last year. And 90 percent of the value of Sotheby’s Impressionist and modern art sale—which takes place two days before the Brexit vote—is in just three works.

Amedeo Modigliani, Jeanne Hébuterne (au foulard), 1919. Photo courtesy Sotheby’s.

The expected downturn comes off the back of tenuous sales at New York’s spring auction season, during which sales almost halved.

“It’s already a fragile situation and any new uncertainty doesn’t help,” Dutch art market specialist Olav Velthuis of the University of Amsterdam told Bloomberg.

A week after the vote, Christie’s will be holding a special curated 250th anniversary sale of British art. The auction includes Old Masters and contemporary works, and is led by Francis Bacon’s 1968 painting, Version No. 2 of Lying Figure with Hypodermic Syringe, estimated at £20 million.

A large number of German works appeared at Christie’s February 2 Impressionist and Modern sale.
Photo: Photo by Spencer Platt/Getty Images

In the event that Britain leaves the European Union, a weak pound could help international collectors find deals at auction. Prime Minister David Cameron made a plea to the British public today, urging residents to “remember they can’t undo the decision we take.”

As it stands, polls suggest that the result of the June 23 vote is too close to call, meaning that any definitive prediction for the results of the London auctions hangs in the balance until the ballots are cast and counted.