Many U.K. companies are not preparing for Brexit because the coronavirus pandemic has depleted their cash reserves, according to a major institute.

Firms are unable to stockpile goods due to the financial damage from the virus. Added to that, they’re unwilling to pay further Brexit-related costs on top of those already incurred preparing for previous deadlines, according to the Chartered Institute of Procurement and Supply (CIPS), a global body with 70,000 members. That creates a challenge for prime minister Boris Johnson and Cabinet Office minister Michael Gove, who leads the government’s Brexit planning.

“Johnson and Gove have to persuade people that it’s really going to happen this time,” John Glen, an economist at CIPS, said by phone. “Companies have got the double whammy of COVID-19, while also stocking up for Christmas and potentially for Brexit.”

Businesses will err on the side of under-stocking going into the Christmas season due to cash-flow constraints, Glen said. That creates the risk of shortages should supplies to Britain be disrupted by the U.K.’s final split from the European Union at the end of this year. The prospect of reduced footfall in shops due to a winter lockdown is also limiting stock-buying.

Britain and the EU are still deadlocked in trade talks over a new economic relationship, with a deal needing to be agreed by October. Without an accord, the U.K. will do business with its largest trading partner on World Trade Organization terms, meaning tariffs and quotas on commerce, exacerbating the economic downturn caused by the virus. Firms also face a new red-tape burden even if there is a free-trade agreement, requiring customs paperwork and extra regulatory approvals to trade with the EU.