Shares in pub group J D Wetherspoon PLC (LON:JDW) sank in early deals as it revealed slower sales in recent weeks and said the EU's stance on Brexit negotiations could hit Eurozone suppliers.
Shares in chairman Tim Martin's FTSE 250 group eased over 5% in early deals at 842.5p.
Like-for-like sales increased by 3.5% in the 13 weeks to October 23 but reduced to 2.3% in the last five weeks.
Martin, a high profile Brexiteer, criticised EU president Juncker's reported stance of intransigence and calls that EU businesses should not negotiate with UK firms.
"This suggested approach puts an unfair burden on the excellent European suppliers with which UK companies, like Wetherspoon, have traded for many decades," he said.
Martin added that the firm anticipated higher costs in the remainder of the current year - for wages, business rates and repairs.