Ryanair boss Michael O'Leary said a UK vote to leave the EU could lead the whole of the 28-nation bloc to unravel.

Speaking ahead of the vote, Mr O’Leary warned that a victory for the Leave camp would signal “an end to the European project.”

While a decision to quit the EU would most likely cause three years of disruption to the UK economy and clip demand for flights for the same period, the impact on Europe as a whole would be more severe, he said in an interview on Bloomberg Television.

Mr O'Leary, who favours an overhaul of the EU to make it less bureaucratic and simplify regulations, said that whatever the result of the vote onThursday the concerns expressed during the debate "should teach the boys in Brussels a lesson."

Asked whether UK prime minister David Cameron had undermined the credibility of the pro-EU argument by suggesting that a Brexit might devastate the economy, Mr O'Leary said that the Remain side's approach should be judged solely in terms of the result. "History is written by the winners," he said.

The chief executive said last month at a Bloomberg Brexit forum in Dublin that Remain needed to “terrify the life out of everybody that there’s a real danger the lunatics on the Leave side are going to win.”

Ryanair has spent €25,000 on an anti-Brexit advertising drive.

Michael Bloomberg, the founder and majority owner of Bloomberg, the parent of Bloomberg News, has publicly supported the campaign to keep the UK in the EU.

Bloomberg