Leo Varadkar has begun his search for a new Tánaiste, with Foreign Affairs Minister Simon Coveney tipped as favourite to take up the role.
Ministers Paschal Donohoe and Heather Humphreys are also being considered to replace Frances Fitzgerald, who resigned yesterday.
Sinn Féin are calling for the Disclosures Tribunal to expand their remit to investigate Frances Fitzgerald, current Justice Minister Charlie Flanagan and the Department of Justice in relation to the whistleblower controversy.
Last night, Charlie Flanagan told the Dáil he was horrified that documents from his department that were not provided to the Charleton Tribunal.
He added that he is 'bitterly disappointed' by the events of recent weeks, and said it has been a 'major challenge' to get complete information in a timely manner.
He told the Dáil: "This is completely unacceptable and I wish to formally apologise to the Taoiseach, to you Ceann Comhairle and to the House."
Meanwhile, Frances Fitzgerald was last night selected as a candidate for Fine Gael in the Dublin Mid-West constituency - only hours after she stepped down as Tánaiste and Business Minister.