The Israel Football Association has accused Republic of Ireland head coach Heimir Hallgrímsson of "hypocrisy and stupidity" over comments he made regarding the upcoming Nations League fixtures between the two countries.
Campaigners have stepped up their bid to convince the Ireland team to boycott Sunday's opener in Hungary, with a group gathering outside the team's hotel in Dublin on Monday evening.
At last week's squad announcement, Hallgrimsson said many squad members were uncomfortable about playing Israel, adding: "We're not playing with genocide, we're playing against genocide."
In a furious response on social media on Monday night, the Israel FA wrote: "We have contributed to the world and humanity in countless fields, earning an impressive number of Nobel Prizes along the way.
"Unfortunately, we have not yet found a cure for stupidity, ignorance and hypocrisy displayed by @IrelandFootball team coach.
"We're not playing with ignorance, hypocrisy and stupidity, we're playing against the coach who embodies them."
A group of over 160 Irish sportspeople have signed an open letter issued by the Irish Sport for Palestine Group urging the Football Association of Ireland to reconsider its previous decision to go ahead with the fixtures.
The letter reads: "This is a significant moment and with this moment you have an opportunity to do the right thing. Not playing the game would be the most sporting thing you could do."
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The FAI said last week that it will reluctantly proceed with Sunday's game in Debrecen, plus a "home" game in Serbia on Oct. 4. No tickets for either fixture will be made available to Irish fans.
The FAI added that governing body UEFA flatly rejected its request to be kept apart from Israel in the draw, and that it had made the decision to continue in order to avoid "significant and lasting harm".
Former Republic star Kevin Kilbane added his voice to the protests, writing in the Irish Times: "Ireland should not be playing Israel. Not in Dublin, not in Hungary, and definitely not a "home" match in Serbia. Not which Israeli forces are committing genocide.
"We as Irish people could have faced down the consequences together. The FAI would have had my support as a former international."