The founder of drinks brand Innocent has launched a scathing attack on the Brexit-backing Wetherspoon boss, accusing him of selling Britain’s economy out for "cheap Chardonnay".
Richard Reed told the Press Association that Tim Martin, chairman of the pubs chain, has helped to "junk" the UK economy.
As part of a stark warning on the impact that leaving the EU is having on business investment, he said: "Brexit is unhelpful, no-one I know is saying it’s a good thing.
"That guy from Wetherspoon (Mr Martin) is talking about it means he can buy cheap Chardonnay from the New World, but I don’t think that’s a reason to junk a country’s economy.
"It’s just not going to help anything, it’s not a good idea to anyone who uses logic, facts and reason."
As well as the collapse in the pound following the Brexit vote, the British economy has slowed considerably and is now being outpaced by the eurozone.
Undeterred, the Wetherspoon boss has been an outspoken proponent of Britain’s divorce from the European Union, issuing countless stock exchange announcements extolling the virtues of Brexit.
He wants Britain to crash out of the EU without a deal and fall back on to World Trade Organisation rules, allowing the country to "follow free trade champions like New Zealand, Australia".
"Richard is being melodramatic," Mr Martin said in response.
"Wetherspoon will benefit from leaving the EU, but so will everyone else in the country.
"History shows that democracy and prosperity are closely aligned, and the EU is becoming more undemocratic."
But Mr Reed - who now runs investment firm JamJar with fellow Innocent co-founders - also warned that British firms are losing out on critical investment because of Brexit.
"I’ve seen three businesses that have had money pulled because of Brexit.
"At JamJar, we are looking at businesses that are focused on the EU, you have to.
"Do you want to be targeting a market of 60 million people or 500 million? The answer is 500 million."
JamJar invests in high-growth firms such as Graze and Deliveroo.
Mr Reed, also a member of pro-single market group Open Britain, sold Innocent to Coca-Cola in 2013 alongside co-founders Adam Balon and Jon Wright for a reported £320m (€m363).
He was speaking as part of his role as ambassador for the Plusnet Pioneers campaign, a programme aimed at helping start-up business owners as they build and grow their companies.
The businessman offers his personal advice on securing funding to help SMEs get investment.
"We need Plusnet Pioneers more than ever in Brexit Britain," Mr Reed added.