Ryanair CEO Michael O'Leary's clothing speaks volumes about his position on the Brexit vote.
In an interview Wednesday with CNBC's "Squawk Box," O'Leary wore a suit with one half showing the EU flag and the other with the Union Jack.
"What more can we do to persuade the U.K. to vote for remain tomorrow," he said.
"I think as the U.K. largest airline, Ryanair has played a leading role in the campaign, and I think one of the things that U.K. citizens can understand that Europe has delivered for them has been the low-fare travel revolution," he said.
U.K. citizens are scheduled to vote Thursday on whether they want the country to leave the European Union.
O'Leary said a Brexit would be damaging to the European and U.K. economies for the next two-to-three years. "There'd be huge uncertainty while Britain tries to negotiate an exit out of the single market and tries to replace it with a whole series of trade deals, which won't get done."
Financial markets have been jittery ahead of Thursday's referendum, with U.S. stocks posting mild gains on Tuesday.