The Tánaiste pledged that the controversy on third-level fees would be dealt with before students sit their Leaving Certificate examinations.
Ms Harney said: "The Taoiseach already indicated during Leaders' Questions in this House yesterday that the intention is to bring clarity to the matter raised before the Leaving Certificate begins."
The Tánaiste, who was taking the Order of Business, was replying to Opposition demands for an emergency debate on the controversy over the possible reintroduction of third-level fees. Rejecting the demands, Ms Harney challenged the Opposition to raise the matter by way of Private Members' business next week.
The Fine Gael leader, Mr Enda Kenny, referred to the "unseemly squabble" between the PDs and the Fianna Fáil in respect of the third-level fees issue.
"Next week is the last week the Dáil will sit before the Leaving Certificate starts and I want confirmation from the Tánaiste that this House will have a proper opportunity to debate the row that is going on between the parties in Government," he added.
The Labour deputy leader, Ms Liz McManus, said her party was seeking a guarantee that the proposal by the Minister for Education to reintroduce third-level fees would be debated in the House next week.
"The reason is very clear. As Deputy Kenny has pointed out, this issue is being debated across the country," she added. "It is a matter of some anxiety for parents and students who are about to sit their Leaving Certificate examinations."
Ms McManus said that the Tánaiste and Taoiseach and the Cabinet seemed to be unable to discuss the matter.
"We have not had a chance to debate this, a central issue in education, in this House even though it has now been discussed in the Seanad. It is being discussed everywhere else but the national parliament," she added.
Mr Paul Gogarty (Green Party, Dublin Mid-West) said continuing worry and instability caused by a lack of clarity on third-level fees "was exacerbated by the comments of the Minister for Education in the Seanad last night". He wondered whether the continuing "battle" being played out in the media between the Coalition partners was "a phoney war".