An internal Fine Gael analysis has predicted the party will gain at least 19 seats, but its electoral partner Labour will increase its seats by five at most in the next general election.
The analysis comes as the party laid out a series of proposals focusing mainly on health and crime at the weekend, in what is expected to be its last ardfheis before the next election. Fine Gael leader Enda Kenny used his keynote speech to attack the Government on both issues.
He claimed an administration that "cannot look after the health of its people does not deserve to be in power", and described the Government's performance on serious crime as "a national disgrace".
He said Fine Gael, along with Labour, would provide an "honest, competent" government. New proposals outlined by the party over the weekend included solving the current accident and emergency crisis within 30 months, including the creation of 15 urgent-care centres to alleviate pressure on A&E units.
It also proposes dropping Government proposals for building private hospitals on spare public hospital land. It proposes instead that public step-down facilities, such as nursing homes, be built on such sites.
Mr Kenny said there would also be a fundamental audit of the decentralisation plan and the scaling-back of some aspects of it, if necessary.
In advance of the conference, the party's director of elections, Frank Flannery, drew up a national constituency analysis, based on private and public opinion polls, candidate feedback and other data, which he said shows that if the party took 26 per cent of the vote, it would take 51 seats in a general election.
His analysis of each constituency, given to the party leadership two weeks ago, claimed that if the party increased its vote share further to 28 per cent, it would add an additional 26 seats to its current total of 32 seats. He played down current opinion poll support for the party, which has recently been put as low as 22 per cent.
His report predicts Fianna Fáil will "move above its current range" in the opinion polls, but that the party would still lose at least 11 seats if it fails to increase its vote beyond 38 per cent. The report says Labour will add between two and five seats.