Talks on a new national agreement have been thrown into crisis with the decision of SIPTU, the State's largest trade union, to withdraw, pending consultations, in protest over the Budget.
The Government also faces more political and public pressure this week over the controversial tax proposal which favours two-income families. The four independent TDs who support the coalition have called for the measure to be changed.
Last night the Kerry South independent Mr Jackie Healy-Rae called on the Minister for Finance to "make some change". He said the level of annoyance he received over the weekend from members of the public was "unbelievable - people are raging".
He said any change would not have to be seen as a climb-down. "It's about putting right what Charlie McCreevy got wrong. I want him to alter it." Fianna Fail and PD backbenchers also reported much criticism from constituents over the weekend.
SIPTU was clearly unhappy with the Budget as soon as it was released. The qualified welcome it received from the Irish Congress of Trade Unions also caused a strong backlash from SIPTU members at local level.
In a statement last night Mr Des Geraghty, SIPTU president, and Mr John McDonnell, general secretary, described the Budget proposals as socially divisive, an "indefensible attack on low-income families" which ran counter "to the tax strategy agreed only last month by all the social partners." SIPTU's national executive is to meet today and tomorrow on the issue, and a meeting will also be held with the ICTU.
Last night Mr Geraghty made it clear that union leaders who helped negotiate the guidelines on Budget changes through the National Economic and Social Council felt betrayed by the package. This view was echoed by the Mr Peter McLoone of IMPACT, chairman of the public services committee of congress.
The Taoiseach continued to defend the Budget over the weekend, claiming it did not penalise single-income families. Mr Ahern told a Fianna Fail conference on Saturday that over the next three years the Government would address the situation for those people who choose to remain in the home.
Nevertheless, there is an emerging consensus within Government circles that the Minister for Finance would have to introduce what one minister described as "a counter-balancing measures to equalise the situation".
The prospect of an equalisation between the tax treatment of single and double-income families increased over the weekend when Mr McCreevy indicated a renewed commitment to the 1997 Fianna Fail pre-election promise to introduce a £2,000 tax-free allowance for stay-at-home parents.
However, the introduction of any significant change in the coming tax year would have serious consequences for the financial arithmetic on which the Budget is based. A senior Government source admitted last night: "Changing the figures announced on Budget day is a horrendous prospect for any Minister for Finance."
The controversial measure will be discussed by the Cabinet on Tuesday while the Minister for Finance will face renewed criticism from his party colleagues at a meeting of the ail parliamentary party on Wednesday.
The coalition will face further Opposition criticism to its measures when the Dail resumes on Tuesday. The leader of Fine Gael, Mr John Bruton, said there was so much money available to the Exchequer that people "can be much better off without introducing any artificial discrimination against one-income families into our tax code".
The introduction of any counter-balancing measure was rejected by the Fine Gael leader, who said Mr McCreevy should "know that the best thing to do, if you make a political mistake, is to simply reverse the mistake, rather than persist in trying to compensate for it by some ad-hoc device".
The Labour Party leader, Mr Ruairi Quinn, said the Budget measure was aimed at "giving more money to people who didn't need it". On RTE Radio, Mr Quinn said it was "outrageous that we are going down this socially divisive road".