The Taoiseach said he understood most employers intend paying the 2 per cent cost-of-living increase due next week.
Mr Ahern was responding to sharp Opposition criticism of a statement made on the issue by IBEC on last Monday. He said that while he did not wish to "wind up" matters, he did not know why the statement was made.
"No employer should try to go outside what was agreed as recently as December 4th last," Mr Ahern said. "They should pay unless they have a case under the terms of the agreement. If they do, they should follow the process."
He said his understanding was that the largest trade union, SIPTU, had only four cases where there was a plea about an inability to pay. "Three of these are the subject of negotiation and there is an understanding on the fourth."
Mr Caoimhghin O Caolain (SF, Cavan-Monaghan) said it was important to recognise the "debilitating effect" of the IBEC statement on the matter, given that it undermined workers' confidence in programmes such as the Programme for Prosperity and Fairness.
Mr Ahern said he was not sure what the IBEC statement on the issue was about. "Perhaps it was just a reminder that conditions were attached to the agreement. If that is what was meant by it, then it was correct.
"If it was about something else, it was incorrect. The process appears to work well, and I urge employers to adhere to it. If not, they should follow its terms and, if there is a dispute, the Labour Court should be involved. I hope that is clear."
The Labour leader, Mr Ruairi Quinn, said the statement was "an unfriendly act and an unnecessary provocation", which did not relate to a specific case and came at a time when negotiations with the ASTI and the consolidation of the social partnership were at a fragile point.
The Fine Gael leader, Mr Michael Noonan, asked if the 2 per cent would be paid to members of unions such as the ASTI, which had opted out of the PPF before the increase was negotiated.
Mr Ahern said the arbitrator had stated what, while the ASTI had pulled out of the PPF, the Government could pay the full amount due as an act of good faith and goodwill.