Fine Gael launched the first attacks as the General Election campaign got underway ahead of the vote in just over three weeks time.
As the parties have been launching their campaigns on the first full day of the election, Ministers said that Fianna Fáil cannot be trusted to deal with Brexit.
MEP Billy Kelleher was in the firing line after he was critical of the Brexit Withdrawal Agreement.
The Ireland South MEP toldthat a range of issues need to be clarified including what rights and entitlements EU citizens will have if they end up living in the UK post Brexit.
The future rights of UK citizens living in the EU are also unclear according to Mr Kelleher.
However, Fianna Fáil leader Micheál Martin insisted Mr Kelleger would vote for the Withdrawal Agreement.
"Any legislation going through Parliament deserves scrutiny," he said. "But he will be voting for the Withdrawal Treaty."
But Fine Gael aimed to stick the boot in through Minister Heather Humphreys.
"This is not the time for the Fianna Fáil junior B team," she said.