On the day the Government of Wales Bill is published, the BBC Wales News website looks at the possible impact of the legislation.
The bill is expected to give the assembly more powers
Just six years after the establishment of the Welsh assembly, the fact that the UK government has decided to revisit the issue of Welsh devolution amounts to an admission of major problems and failures in the original settlement.
Such problems were predicted at the time.
Labour's Welsh devolution policy was shaped with one eye on what was to prove a difficult referendum campaign.
Compromises aimed at maximising political support and minimising public opposition have proved clumsy in practice.
The new bill is expected to contain a series of measures to strengthen the powers of the assembly and assembly government.
The bill falls short of giving the assembly full Scottish-style legislative powers as recommended by the all-party Richard Commission, although such powers could come in time following a new referendum.
The main proposals in the bill are expected to be:
- A separation of the roles of the assembly itself and the assembly government.
The original Government of Wales Act gave substantial powers to the assembly itself and its all-party committees in developing and implementing policies.
The new act will see Cardiff Bay moving to a Westminster-style system with government ministers framing policies while the assembly concentrates of scrutiny and legislation.
This is similar to the change seen in most Welsh councils over the past decade with a cabinet system replacing the old committee system.
This move is broadly supported by all the parties in the assembly who are frustrated that the assembly as whole is either blamed for or credited with policies that are originated by the governing party.
- A new fast-track system
Assembly members (AMs) have been frustrated by the so-called "legislative log-jam" in parliament where assembly-prepared legislation has to compete for time with bills prepared by Whitehall ministries.
The new system would allow the assembly to draw up legislation following votes in the Commons and the Lords to approve the principal of the proposed measure.
- A mechanism for the assembly to receive full law making powers following a further devolution referendum.
For such a referendum to be triggered a broad consensus would be required in the assembly.
This clause in the bill is seen as crucial by AMs who fear that further devolution could be held up by Welsh MPs worried about a further erosion in their power and influence.
- The fourth main proposal is likely to prove the most controversial.
To ensure that the assembly broadly reflects the share of the vote received the forty constituency AMs 20 members are elected from regional top up lists.
Labour AMs have developed a strong dislike of the list system, possibly since no Labour AMs are elected by this method.
Labour in particular are irritated by candidates who lose in constituency contests entering the assembly by what they see as a "back door".
If the bill is passed unchanged and survives a possible legal challenge under the Human Rights Act, candidates will be prevented from standing in both sections - a move the opposition regards as blatantly partisan.