Fianna Fáil is upping the ante in its key demand for a €5-per-week increase to the State pension.
A week out from the Budget, the firm stance will heighten expectation that the increase will have to be delivered.
Social Protection Minister Leo Varadkar is warning Government colleagues that he needs to be given the resources to meet all the clamour for increases.
Senior Fine Gael figures have also been critical of Fianna Fáil's approach of publicly setting out its shopping list.
But Fianna Fáil welfare spokesman Willie O'Dea has delivered scathing criticisms of Mr Varadkar and accused the minister of "spinning".
"Anything less than a fiver extra per week would be seen as extremely mean, particularly in view of definitive commitments in the election manifestos of both Fianna Fáil and Fine Gael before the General Election," Mr O'Dea told the Irish Independent.
Mr Varadkar has said he would need up to €350m in total next year just for pension demands. The €5-per-week hike would cost €150m, while the extra numbers qualifying for pensions would cost some €200m.
The parties are also in dispute over entitlements for the self-employed.