SIPTU wants all workers earning less than £5 an hour removed from the tax net, and those on average earnings to pay tax at the standard rate.
In a policy document entitled Budget Strategy for the Millennium: Growth Sustained with Fair Sharing of Gains, SIPTU has accused the Government of failing to make any progress on its electoral commitments to place 80 per cent of taxpayers on the lower standard rate of tax.
The document was adopted by the union's officer board at a meeting in Dublin yesterday. In it SIPTU calls for tax relief to be concentrated on low to middle earners, for the move to tax credits to be completed as soon as possible, for a "significant increase" to be made in the PAYE allowance and for a widening of the standard rate band.
It says its objectives can be achieved by an increase of £2,500 in the single person's personal tax allowance, a further increase of £2,500 in the PAYE allowance and an increase of £3,200 in the single person's standard rate tax band.
It puts the cost of these reforms at £1,900 million.
In a statement after the meeting SIPTU said it was "demanding a tax package in this December's budget of at least £950 million to make real progress towards achieving an equitable tax system as we move into the next century".
The union intends evaluating the budget on the basis of the progress achieved in meeting its objectives.
"The taxation measures of the December budget will therefore be a critical test as to whether or not the Government is making an appropriate contribution to establishing a positive environment for further economic and social progress upon the conclusion of Partnership 2000," SIPTU said.