The Government has still not tabled costed or detailed proposals on the critical issues of pay restoration or pensions at the public service pay talks, which are continuing at the Workplace Relations Commission.
Some sources have reported that progress is being made as they continue to negotiate on the non-pay agenda of productivity and reforms.
However, contentious issues including outsourcing and working hours remain unresolved.
The talks are expected to continue late into the night, but it is still unclear whether a deal can be secured.
If no deal is done, talks may have to resume at the weekend as the WRC has other commitments tomorrow and on Friday.
Earlier, public service unions voiced concern about the prospect of securing a new pay agreement for Government employees.
SIPTU Health Division Organiser Paul Bell is quoted on Twitter saying: "Extremely negative engagement this evening. Difficult to see a way to resolve any of our members' outstanding claims".
The negotiations were adjourned at around 11pm yesterday to allow the Government side to "crunch some numbers".
At that point, management had still not tabled any detailed figures on the key areas of potential pay rises or increased pension contributions.
In an online update this morning, the largest public service union, IMPACT, said that there has to be some nervousness that the Department of Public Expenditure and Reform is still doing its sums at this stage.
It said that this late in the process, that number-crunching can only be about pay and pension costs, with unions yet to be given a formal pitch on the amount of cash available to fund what has now been clarified as a three-year deal.
The update states that the chief negotiators have clearly had some conversations on the core matter of incomes.
It goes on: "... while turkey-talking about money always tends to come at the end of negotiation like this, there has to be some nervousness that DPER is still doing its sums at this late stage".
It states that while a "fair bit of progress" was made on non-pay issues, a number of headaches remain including outsourcing.
IMPACT tells members that by this afternoon, they should have a better idea about whether or not there is "enough in the pot" to fashion a deal that can seriously be put to ballot.
- but sources are stressing that there is still no guarantee of a deal, as management and unions remain very far apart.
NBRU chief warns over potential transport chaos
Meanwhile, the General Secretary of the National Bus and Rail Union has said there is potential for travel chaos this summer.
Dermot O'Leary told RTÉ's Morning Ireland that every time staff at CIÉ companies seek a pay rise, the Government says no.
He said that if the Government wants a role in industrial relations, it must stop making decisions "in the shadows".
He added that revenue and passenger numbers at Irish Rail have risen beyond Celtic Tiger levels and the National Transport Authority has said the company cannot continue to be under-funded.
He said a lump sum of €125 million should be invested.
Mr O'Leary said the NTA did not recommend this money went on pay, but it is not tenable to tell those who have contributed to the company's success that they should not get a pay rise.