Peter Casey's come under fire from his rivals in the first TV debate featuring all the presidential candidates.
The businessman was accused of racism by Sean Gallagher after he repeated his controversial claim that Travellers aren't an ethnic group.
Mr Gallagher said: "You should go spend some time with the community and when you understand the challenges they have faced" - Mr Casey interrupted: "It's like giving chocolate to a diabetic - you're not helping them".
Mr Gallagher suggested: "That's a racist comment, Peter - I'm not calling you a racist but that's a racist comment".
Michael D Higgins during the Pat Kenny debate on Virgin Media One | Image: Virgin Media
Michael D Higgins faced more questions about his spending and travel arrangements.
Liadh Ní Riada challenged the president when he said he wouldn't allow an audit of Áras spending until after the election.
Mr Higgins said: "If you want an auditing system in the Office like that it should be one that would work for anyone that comes after me.
"It would be entirely wrong to either personalise or politicise this."
"I can say the end point is that all of the money is signed off by the Comptroller and Auditor General".