The HSE will save up to 100 million euros if plans to increase the working week are introduced.
According to the Sunday Times, Health Service negotiatiors have had been in talks with representatives for the 100,000 workers to try to add an extra two hours to the working week - but talks have stalled.
A new 1.5 hour offer is expected to be tabled shortly as part of talks on a second Croke Park deal - producing savings of between €80m and €100m.
Last week, Public Expenditure Minister Brendan Howlin said the deal on the promissory notes will not affect the €1bn in savings the government hopes to make in the new Croke Park agreement.