Pub chain JD Wetherspoon saw profits drop by 19% in the six months to the end of January, it has reported.
The company said repairs, rising utility bills, interest payments and workforce costs were behind the falling profits. However, revenues and sales were up by 7% and 6% respectively.
Chairman Tim Martin, who is a high-profile supporter of a no-deal Brexit, accompanied the announcement with concerns that the process of leaving the UK was being reversed after this week's votes.
On Thursday, MPs voted to extend Article 50, meaning that the UK will not leave the EU on 29 March, if the EU agrees. That decision has increased speculation that Brexit could be stopped altogether.
Martin said that would have "adverse economic consequences", blaming "the establishment" for a "barrage of negative economic forecasts".
The Wetherspoon boss is currently touring 100 of its 900 pubs to discuss the benefits of leaving the European Union without a deal.
Martin has announced that it will replace champagne and prosecco with sparkling wine from non-EU countries, and German beers will be replaced by wheat beer and alcohol-free from the UK.