Fianna Fáil leader Micheál Martin attacked Ireland's EU Commissioner Phil Hogan yesterday, accusing him of making a "coded, partisan intervention" on behalf of Fine Gael in the General Election campaign.
As Britain prepares to formally depart the EU at 11pm tonight, Mr Martin said Mr Hogan, a former Fine Gael cabinet minister, should "stay out of domestic Irish politics" for the final week of the campaign.
He was responding to the EU trade commissioner's comments on Wednesday to RTÉ where he said he was "very concerned" by "a lot of complacency" in Ireland about forthcoming trade talks between the EU and the UK, with a crash-out Brexit still possible.
Mr Hogan said that people in Ireland needed to "come out of their slumber".
This came after Tánaiste Simon Coveney warned earlier in the day that Brexit was "coming at us like a freight train".
Speaking in Dublin, Mr Martin said: "I would make the point that they [Fine Gael] are politicising it. I think Phil Hogan should stay out of domestic Irish politics now for the next week.
"That was, to me anyway, a coded, partisan intervention and I just want to make this key point... I kind of remember before Christmas this was a great deal. Everything was great and now in the last 48 hours there is a freight train coming down the tracks.
"Big Phil is telling the Irish people that they are in a slumber and so there is a new story being created, a new narrative has been created that things are desperate altogether and I think people are going to see through that, as an election creation designed to try and frighten people into voting in certain directions. I don't think it will work."
Mr Hogan hit back, saying he has "never interfered in domestic politics since becoming EU commissioner".
He said comments he made this week were in the context of it being the eve of Brexit. He said he was sure it is the case that an alternative government could do as well as Fine Gael on Brexit.
He told RTÉ's 'Today with Sean O'Rourke': "I know people are sensitive at election time but I'm not sensitive about telling the truth about the position and alerting people out of their complacency."
Finance Minister Paschal Donohoe defended Mr Hogan's remarks, saying he was merely "outlining the reality that our country is facing".
Mr Martin was speaking after he delivered a speech to the Institute for International and European Affairs (IIEA) where he said that a Fianna Fáil government would carry out a "rapid review" of the Brexit loan and support schemes and will establish a new Department of Higher Education and Research to respond to the challenges presented by the UK's departure.
Meanwhile writing in today's Irish Independent, the presidents of the European Commission, Council and Parliament warn Britain not to undercut the EU on environment, labour, taxation and state aid. The blunt message is if the UK tries that, it will lose on access to the single market.
Otherwise, they strike a more positive note saying they hope a new EU-UK relationship will be positive and based on trust.