JD Wetherspoon has squared up to Heineken in a 76 million euro dispute which has seen the pub chain ban the brewer's products from its more than 900 premises.
The pubs firm accused the brewer of throwing the first punch in the scrap which centres on its new site in Dun Laoghaire, a seaside town near Dublin.
Wetherspoon said Heineken had refused to supply Heineken lager - Ireland's biggest selling draught beer - and Murphy's stout to the pub.
It said the Dutch-owned brewer had also demanded personal guarantees on the payment of the pub's bill from chief executive John Hutson.
Wetherspoon did not disclose further details of what the row was about but it has already fallen out with British drinks firm Diageo over prices at its first Irish pub, The Three Tun Tavern in Blackrock, which opened earlier this year.
It also said it had been selling Heineken lager and Murphy's at under three euros a pint at the Three Tun, against an average price in Irish pubs of around five euros.
Wetherspoon said it would no longer trade with Heineken at any of its 926 pubs in the UK and Ireland - business worth about 76 million euro a year.
But the decision leaves the firm with a decision over what stout it can supply to its customers in Ireland now that it does not sell either Guinness or Murphy's.
A Heineken spokesman 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 JD Wetherspoon in the UK over a 35-year period and it's 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. It is not our intention to comment any further."