SIPTU president Jack O'Connor has called for compulsory contributions by employers to occupational pension schemes if the Government's voluntary scheme fails to improve its take-up.
He accused employers of being unwilling to carry their fair share of occupational pension provision.
Mr O'Connor also called for tax incentives to encourage those saving in the Government's special incentive accounts to transfer their money to retirement funds.
Many people have either insufficient pension provision or none at all. A recent initiative to encourage voluntary investment in PRSAs has had a slow take-up.
SIPTU warns that if the PRSA situation does not improve dramatically within two years, employers should be forced to contribute to occupational schemes because they are failing to carry their share of the pensions burden.
The union is also demanding tax incentives to encourage SSIA savers to transfer their money into retirement funds immediately.
SIPTU also wants the State to open pension schemes for children born after 1 January next, a €20 a week hike in old age pensions, and tax credits for low paid workers entering pension schemes.
IBEC Director of Industrial Relations Brendan McGinty said mandatory pension provision by employers was an unrealistic proposition, which could cost jobs.