The Minister for Social protection is expected to be elected Taoiseach this afternoon
Former Minister for Communications Pat Rabbitte said Fine Gael leader Leo Varadkar is facing into challenges during his tenure as Taoiseach.
Outlining the Health and Housing portfolios as areas of concern, Rabbitte said Varadkar should also not understimate the difficulties facing power-sharing in Northern Ireland.
"There now is a disposition to re-establish the institutions at Stormont," he said on Newstalk Breakfast. "But will the DUP work with the new Taoiseach to moderate the stance of the looming wing of the Conservative Party?
"Will he able to work with the First Leader and the Deputy First Leader?"
Rabbitte continued, saying that nobody understands the stamina required to run the country until such a time when they are in the position themselves.
He called Varadkar "an extremely talented individual" and said that his success as Taoiseach was necessary for Fine Gael at the moment.
Varadkar is set to be elected Taoiseach today - with an even smaller majority than Enda Kenny.
He'll be nominated by the Dáil this lunchtime, and will announce the members of his new cabinet this evening.
Meanwhile in the UK, there's speculation that a deal between the DUP leader and the British Prime Minister could be finalised today.
Theresa May is in talks to secure the support of Arlene Foster's party for a minority Conservative government.
The DUP leader didn't return to Belfast as planned yesterday, and said the talks could wrap up "sooner rather than later".