Torfaen AM Lynne Neagle lead a short debate on the impact of housing welfare reform on Wales.
She said that 46% of working age benefit claimants will be affected by housing reform welfare cuts, 40,000 claimants in total.
The Welfare Reform Bill was
in Westminster earlier this year.
Ms Neagle claimed that the reforms could lead to 4000 households being made homeless.
Housing Minister Huw Lewis responded to the debate stating that the UK government were "demonising the poor".
He said that it was "the intention of the UK government is that we (the Welsh government) or local authorities pick up the pieces".
He said it would be "difficult to quantify" the full effect of the reforms until they are fully underway.
Liberal Democrat AM Peter Black defended the coalition government in Westminster by stating that the previous Labour government had "teething problems" with housing reform they introduced.
"Everyone needs to work togther to ease these teething problems."