Taoiseach Leo Varadkar has moved to distance his party from Sinn Fein amid mounting calls for him to scrap legislation that will overhaul how judges are appointed in the Republic.
The Fine Gael leader has said that there was "no deal".
However, Mary Lou McDonald's party said Mr Varadkar "can call it whatever he wants" but Sinn Fein has agreed to backing the Judicial Appointments Bill in exchange for progress on sentencing guidelines.
The deal has caused unease in Fine Gael with Finance Minister Paschal Donohoe stating he would "prefer" if the Government could pass the law with the support of other members of the Opposition. The Bill, which will see the establishment of an advisory committee with a lay majority advise the Irish Government on judicial appointments, has been beset with difficulties.
Irish Labour leader Brendan Howlin criticised both the deal and the Bill as a farce that has descended into a crisis.
"It is becoming more evident now that Fine Gael is content to rely on Sinn Fein support to remain in power and satisfy the demands of Transport Minister Ross, and that Sinn Fein is happy to give it," he said.
The legislation was a red line issue for Mr Ross to secure his agreement to back Mr Varadkar's minority administration.
The focus on the deal between Sinn Fein and Fine Gael sharpened in recent days following comments made by Sinn Fein party whip Aengus O Snodaigh, who claimed judges in the Special Criminal Court have shown an "anti-republican bias", claims dismissed by the Justice Minister Charlie Flanagan as "groundless".
Mr Varadkar said there has been a commitment on sentencing guidelines.
He said voting records show Fianna Fail and Sinn Fein are far more likely to vote with each other and that Fine Gael and Sinn Fein doing so was "exceptional".