Taoiseach Leo Varadkar says he does not want a ''cliff edge'' end to the confidence and supply arrangement.
The deal keeping the government up is due to run out at the next budget but the Fine Gael and Fianna Fáil leaders haven't started re-negotiating it.
Mr Varadkar wants to do so before the budget, while Micheál Martin says they'll wait until closer to January.
However, the Taoiseach doesn't think that is a good idea.
"You know, we're talking a lot about a cliff edge Brexit and why that would be not in the national interest," he said.
"It would put us in a situation where we're trying to negotiate extensions to the confidence and supply agreement right after a budget where we're in the middle of what could be crucial talks on Brexit," he said.