Labour's suggestion that the assembly should precept on the new unitary councils would turn it into a 're-born county council for Wales', it said.
The CWD has endorsed none of the models suggested by the Labour Party in its consultations on a Welsh assembly - from a minimalist monitoring body to a full-scale legislature.
Selection of the final option is a matter for political choice, it says.
'The CWD has consistently argued that the reform of local government into unitary authorities and the establishment of a Welsh Assembly should not lead to a transfer of functions from central to local government,' it says. It warns that ministers and MPs might be happier with an assembly that takes powers from local, not central, government.
The CWD puts the various options for the Welsh assembly into three categories:
- The minimalist model. The assembly is consulted on legislation, scrutinises value for money and takes on a strategic and co-ordinating role with local government. 'It is likely such an assembly would seek to gain powers over local government,' the CWD says
- A less minimalist model. This would take on power from the secretary of state and quangos. It would have political responsibility for the Welsh Office and other public bodies
- The maximalist model. The assembly would raise its own revenue through taxation in Wales and would be able to pass legislation.