Mr John Bruton and his opponents will today canvass intensively for the votes of a handful of undecided parliamentary party members whose decision will determine the outcome of the struggle for the party leadership.
As both sides claimed victory last night, it appeared that each camp had the support of close to 30 TDs, senators and MEPs.
With 37 votes needed to guarantee success, lobbying of the waverers today and tomorrow morning will decide whether Mr Bruton can hold on to the party leadership at tomorrow afternoon's crucial parliamentary party meeting.
Sources in each camp last night claimed they had more than 40 votes - a mathematical impossibility with an electorate of 72. Figures on both sides, for example, claimed Mr Alan Dukes would support them. Mr Dukes would not take calls from reporters yesterday.
The undecided are said to include senators Mr Tom Hayes, Mr Dino Cregan and Mr Ernie Caffrey and TDs Mr Sean Barrett and Mr Michael Ring.
Four of the 23 front-bench members have declared against Mr Bruton, with two more expected to do so and another also considering voting against the leader. Mr Bruton has therefore decided to avoid a confrontation at today's front-bench meeting, choosing not to seek an endorsement from his senior colleagues as he did during the last challenge in November.
Instead the front bench will confine itself to discussing the mechanics of the debate, which should last from 2.30 p.m. until well into the evening.
It has become clear that deputies, senators and MEPs are veering strongly towards Mr Michael Noonan over Mr Jim Mitchell, should a leadership contest take place. However there is a widespread expectation that another candidate would emerge, and would be backed by many of Mr Bruton's loyal supporters.
Mr Bruton is showing no sign of contemplating defeat. Writing in today's Irish Times, he accuses his opponents of having been "panicked by an opinion poll".
The front-bench members who have said they will vote against the motion are Mr Bruton; his brother Richard; Mr Charles Flanagan; Mr Phil Hogan; Mrs Nora Owen; Mr Ivan Yates; Mr Bernard Allen; Mr Enda Kenny; Mr Maurice Manning; Mr Gay Mitchell; Mr Denis Naughten and Mr Brian Hayes.
Those opposing him are Mr Noonan, Mr Mitchell, Mr Michael Finucane and Mr Alan Shatter. Mr Jim O'Keeffe is also believed to be planning to vote against Mr Bruton. Ms Dierdre Clune, daughter of former Minister Mr Peter Barry, declared her intention to vote against Mr Bruton in a statement issued at midnight.