Chairman Tim Martin confirmed the managed operator had ended its 35-year relationship with Heineken.
The group said that Heineken also demanded personal guarantees from Wetherspoon chief executive, John Hutson, in order to supply any other products for the Dun Laoghaire pub. Heineken lager is Ireland's biggest-selling draught beer.
Martin said: “We have been trading with Heineken for 35 years and they have never requested personal guarantees before.
“It’s obstructive to do so now, especially when we made record profits of around £80 million last year. The refusal to supply Heineken lager and Murphy’s just before the opening of our new pub in Dun Laoghaire, which represents an investment by us of nearly four million euros, is unacceptable and hard to understand.”
Wetherspoon has been selling Heineken lager and Murphy’s at under three euros a pint in its first pub in the Republic of Ireland, The Three Tun Tavern at Blackrock, against an average price in Irish pubs of around five euros.
The new Forty Foot pub will open next Tuesday (16 December) and is the company's second in the Republic of Ireland.
Update - Heineken response:
A spokesman for Heineken UK said: “We are aware of the comments made by JD Wetherspoon and its chairman this morning. Heineken UK has had a long standing and successful relationship with JDW in the UK market over a 35 year period, and it is unfortunate that commercial issues in Ireland between Heineken Ireland and JD Wetherspoon have led to the current situation.
"We are seeking a resolution as soon as possible, and it is not our intention to comment in any further detail at this point."