Fianna Fáil should not be given an overall Dáil majority in next month's general election, Mr Des O'Malley of the Progressive Democrats has warned.
The 1987-89 Fianna Fail government led by Mr Charles Haughey, through "its arrogance and its abuse of office, has made the most compelling case of all for the need for coalition government", he said.
"I hope that there will be no return to the single-party rule next month. This is coalition country now and I trust that it is going to stay that way," Mr O'Malley told the Association of European Journalists.
His remarks come as confidence quietly grows within Fianna Fáil that it could win an overall majority in May - although FF politicians are discounting the possibility in public.
"Coalition has been good for this country. There appears to be a general recognition of that fact now.
"And yet I hear murmurings in the media about a possible return to single-party government," Mr O'Malley said.
The Haughey-led 1987-89 government was "still enveloped in controversy. Indeed, the controversies often seem to involve envelopes.
"It is, perhaps, the most analysed, the most examined, the most scrutinised, the most investigated government in the State's history. And rightly so," Mr O'Malley said.
"Oscar Wilde once said that he could resist anything but temptation. Politicians have to resist temptation all the time, but it is, shall we say, somewhat easier to fight that demon if you have a coalition partner by your side."
The history of coalitions since has proved his case, he believed: "It is no coincidence that this has been perhaps the most successful and progressive period in the history of the State."
Launching another attack on Sinn Féin, he said he was confident that the party will not in government "here any time soon", regardless of the result of the general election.
During his time as Minister for Justice in early 1970s, the IRA made "clear their contempt for this State and made no secret of their desire to destroy it".
Sinn Féin professes to be "very upset about some of the awful things that our politicians got up to" during the 1980s.
"And there is no doubt that the Lawlors and Lowrys of this world have created an opening for them and given them an opportunistic avenue of attack.
"The Provisionals are horrified at the activities down here of our brown-envelope brigade. But they are not the least bit horrified by the activities of their own brigades during the same period."
