Sinn Féin's sitting MEP Matt Carthy believes his Midlands North West vote haul may be up to 2% lower than Friday's exit poll suggested and that he will be in a "dog fight" for the final two European seats.
Mr Carthy admitted he is concerned about the situation as he separately said he believes Fine Gael MEP Mairead McGuinness and Independent MEP Luke Ming Flanagan are likely to take the first two of the four seats on offer.
Speaking to the Irish Examiner from the local elections Monaghan count centre before he travels to the Midlands North West count centre in Castlebar, Co Mayo, tonight, Mr Carthy said it is far from clear how the constituency race will pan out.
However, he said based on the small number of tallies he has seen so far, he is concerned the exit poll overstated his first preference support and that this could unexpectedly drag him into a four-way battle for the final two seats.
"I entered the race expecting to be in the running for one of last two seats. It's just based on anecdotal evidence I've seen so far, but I think I'll be on 2% less than the exit poll. I'll be in a dog fight for the final two," he said.
It is widely expected Ms McGuinness will surge home in the first two counts.
However, initial reports suggest her transfers may split between Fine Gael running mate Maria Walsh and Mr Flanagan.
This would be a surprise development that, if proven correct and coupled with a likely stronger than expected poll result for Mr Flanagan, will help to push the Independent MEP into a safer than expected position.
Of the two remaining seats, Mr Carthy, Ms Walsh, Greens candidate Saoirse McHugh and Independent Peter Casey and are also in the running, with the exit poll on Friday suggesting Ms McHugh was just ahead on first preferences.