Contenders will go into battle amid claims of 'dirty tricks'
The two frontrunners in the Fine Gael leadership battle believe their campaigns will be energised by a series of high-profile endorsements from ministers and TDs in the coming days.
Leo Varadkar and Simon Coveney will today step up their bids to succeed Enda Kenny in a race that senior party figures fear will become deeply personal and divisive.
Supporters of both candidates last night ramped up their negative campaigning, which has been intense and constant despite public denials from both ministers.
Mr Coveney's camp has accused Mr Varadkar's supporters of "dirty tricks" following claims that the Cork TD will use his family's personal wealth to fund his election campaign.
But senior sources in Mr Varadkar's inner circle said Mr Coveney's camp is intent on "attacking" his character.
One source last night said Mr Varadkar is braced for further negative campaigning, adding: "They're getting very desperate". Mr Varadkar expects a flurry of TDs and senators to publicly endorse him in the coming days, following the decision by Mr Kenny to step down as Fine Gael leader from midnight.
All eyes will be on Cabinet heavyweights such as Paschal Donohoe, Michael Noonan, Heather Humphreys and Charlie Flanagan, all of whom have refused to publicly declare.
Education Minister Richard Bruton will also make a much-anticipated statement.
Mr Bruton has so far refused to rule himself out of the race, with some within the party describing him as the "compromise candidate".
Mr Varadkar has no public events scheduled over the next 24 hours, but sources say this could change.
Last night, the Dublin West TD tweeted: "Thank you Enda. FG's most successful leader. Brought FG from decline to success, Ireland from brink of bankruptcy to prosperity."
Mr Coveney is due to address the media, before attending events in Clare and Cork tomorrow and Saturday.
The Housing Minister described Mr Kenny as "a towering figure in modern Irish history". Meanwhile, Independent Alliance minister Finian McGrath confirmed he has spoken to both Mr Varadkar and Mr Coveney amid concerns that the change of Taoiseach could trigger an election.
Mr McGrath added that he and other Independent ministers have their own "shopping lists" and that these will be discussed with the successful candidate.
"Both of them, in fairness to Simon and Leo, have said they would be very interested in sticking to the three-year plan - to implement as much as possible the programme for Government."
Mr McGrath said his judgment is that there won't be an early election, but added: "You never know in politics."
Asked if the Alliance would have fresh demands for the next Taoiseach, he replied: "We'll be sitting down with the new leader and the new Taoiseach of course and we will be pushing forward the particular projects that we have in mind.
"We all have our own little shopping lists.
"That's the reality of politics. But we will be highlighting certain key issues that need to be implemented and we need to add a bit of impetus."
His own list includes seeking to get the proposed new accident and emergency department in Beaumont Hospital into the Capital Plan for this year.