Plaid Cymru AM Rhodri Glyn Thomas accused the Welsh government of failing to protect the most vulnerable people in Wales, during a statement on council tax.
Local Government and Communities Minister Carl Sargeant was making a statement on new arrangements to provide support for council tax in Wales, on 22 May 2012.
According to Mr Thomas these new arrangements are unfair and will fail to protect people in the poorest areas of Wales.
The minister insisted he was "profoundly concerned" by the UK Government's plans to abolish Council Tax Benefit and outlined the Welsh governments proposals to develop and implement a new scheme.
Mr Sargeant said: "Almost 328,000 households in Wales - roughly 1 in 4 - currently receive some form of support with their council tax bills.
"Whilst I have deep reservations about the UK Government's decisions and their resulting impact, we have a moral obligation to develop a replacement scheme.
"If we fail to do so, some of the most vulnerable people in our society will experience severe financial hardship."
However Rhodri Glyn Thomas AM accused the government of "doing nothing" to protect the most vulnerable in society.
The minister appeared surprised by the members' comments and stressed that tackling the longer term causes of poverty in Wales was a Welsh government priority.