The 2017 London Book Fair officially opened today, and at the fair’s opening press conference LBF director Jacks Thomas smiled as she raced through her slides. For the second year in a row, Thomas noted, publishers headed to London with fairly strong sales in the U.K. (and the U.S.), with literature in translation growing, children’s and digital audio surging, and print books—and bookshops—looking especially resurgent.

But following Thomas on stage at Olympia’s Grand Hall, a panel discussion broke down the potential effects of the looming Brexit on publishers, one day after British lawmakers cleared the way for the formal work of leaving the E.U. to begin.

“The U.K. now has around two years to work out what type of country it wants to be in the future,” said U.K. Publishers Association chief executive Stephen Lotinga. “The referendum in June may have provided an answer to our membership in the E.U., but many questions remain about the type of nation we want to be in the future. And one of the reasons U.K. publishing is so successful is because of the type of country we are: open, diverse, international. How and whether these values are sustained in the future will have enormous consequences for our industry.”

In his talk, DK Publishing CEO Ian Hudson said that, for publishers, the devil will be in the details when it comes to Brexit.

“You may or may not like the outcome of last year's referendum,” he said. “Like me, you may believe that socially, culturally, and in terms of standing we will be much the poorer for [leaving the E.U.]. But it's far from clear to me that we have to be worse off economically.”

The U.K. now has around two years to work out what type of country it wants to be in the future.

Hudson then ran down a number of issues that DK—a global publisher, doing in business in 100 countries—now faces: chief among them, retaining good, international talent. Hudson said the government should immediately guarantee the right of international workers to stay in the country, saying it was “inhuman” to use their live and careers as negotiating chips.

“Talent diversity and internationality is crucial to DK, and I would suggest that over the past couple centuries it has been crucial to the U.K. and its development as a highly creative society,” Hudson said, noting that of the 500 employees in DK’s U.K. office, 81 do not have British passports. “Diversity and creativity go hand-in-hand. We need to be able to retain our European talent, and we need to be able to recruit European talent, and talent from outside Europe, so they can help us continue to develop books that will appeal to global markets.”

In the Q&A period, HarperCollins CEO Charlie Redmayne backed up Hudson, saying that Polish workers in Harper's Scottish outposts are "going back home" as uncertainty looms over whether they will be allowed to stay in the U.K. These Brexit departures, he said, are already impacting business. "Not giving security on residency will impact U.K. businesses and jobs," said Redmayne.

Currency fluctuations are also an issue, Hudson noted. Although he conceded that the weak pound has helped the export business, and could help U.K printers compete internationally, it has also significantly increased DK’s overseas printing costs as well as the costs of maintaining international offices. But most damaging, fluctuating currency is hindering the business as many DK customers must commit to taking quantities of books 12 or 18 months before they have to pay for them.

Hudson also urged the U.K. government to commit to free trade principles. “It is a well-established fact: trade barriers destroy economic value,” Hudson said. And, he urged the U.K. to find a way to remain engaged on copyright issues in Europe.

“Copyright, intellectual property, and piracy protection are fundamental, and the loss of our seat at the E.U. table and the ability to influence E.U. copyright decisions is a backward step,” he said. "Over many years we've proven to be a voice of reason at the E.U. table that has helped deliver copyright frameworks and intellectual property rights frameworks that we can all work with. We just voted to lose that voice. So we need to find another way of offering influence.”