The housing organisation Threshold has called on the Government to live up to its commitment to house disadvantaged people amid alarm that this year's target for social housing will not be met.
Threshold predicts that 4,000 units of social housing will be built this year, a 39 per cent drop on the target of 6,600 units.
Ms Aideen Hayden said last year's output of 5,077 housing units should have been 19 per cent higher to reach the Government's target of 6,100 units.
"This widening divergence between promises and delivery will have serious consequences on the ever-increasing waiting lists for social housing," she added.
A total of 48,413 households in need of housing were assessed by local authorities last year as suitable for social rented housing.
Ms Hayden said affordable housing schemes were fashionable, as shown by the Government's promise of 10,000 discounted houses for sale under the new social partnership agreement, Sustaining Progress.
"However, affordable housing schemes do little to help the worst off in our society because home ownership is beyond their reach.
"Effective social housing programmes help the economically and socially most vulnerable in our society."
Meanwhile, €39 million in funding has been approved for accommodation and related homeless services in the Dublin area.
The Minister for Housing and Urban Renewal, Mr Noel Ahern, approved the funding yesterday, almost half of which is allocated for accommodation, out-reach and settlement services.