Plans to change the powers of the Welsh Government and the National Assembly are to be published today.
The proposals will be set out in a draft Wales Bill to be unveiled by the Welsh Secretary Stephen Crabb.
It'll be based on a blueprint that was agreed in talks between the four main parties led by Mr Crabb in the aftermath of Scotland's independence referendum.
Those proposals included:
Energy projects up to 350megawatts should be decided by Welsh Ministers. This would include most onshore wind farms and renewable technologies to harness tidal power
The National Assembly should have powers over the development of ports to improve Wales’s transport infrastructure.
The National Assembly should have the power to lower the voting age to 16 for Assembly elections. The Assembly already has the power to lower the voting age to 16 for a referendum on devolving income tax powers.
All powers relating to Assembly and local government elections should be devolved. This includes deciding the electoral system, the number of constituencies, their boundaries, the timing of elections and the conduct of the elections themselves.
Welsh Ministers should have the power to appoint one member of the Ofcom board to represent Welsh interests.
A review should be carried out of Air Passenger Duty which could open the door for it to be devolved to Wales.
What's likely to prove most controversial is something that's had seen the most agreement in the run-up to the talks.
All parties agreed to move to a form of devolution known as the 'reserved powers model' in line with what happens in Scotland - where it's assumed that the Assembly has full control over all devolved areas.
In practice that'll mean a long and detailed list of exceptions which has already led to claims that the UK Government is 'rolling back' devolution.
The First Minister called for the whole process to be delayed while disagreements were ironed out.
That's been rejected by the Welsh Secretary who says there'll be plenty of time for discussion in the consultation period which begins today and is expected to end next February.
You can see what Stephen Crabb said to me about these differences when I spoke to him last week in the video below.
'End drip-feed devolution'
Plaid Cymru says it's hoping that the bill will bring an end to 'drip-feed devolution.'
Plaid Cymru hopes the Draft Wales Bill will be a radical and robust piece of legislation that will equip our National Assembly with powers over important fields which affect people's everyday lives. The Wales Bill is a golden opportunity to give our nation a strong and fair settlement which puts it on an equal footing with the other nations of the UK. Wales is not a second class nation and our people deserve nothing less than parity. If the Secretary of State for Wales agrees, I hope he will use this Bill to honour and realise that belief.
'Clear the murky waters'
The Welsh Conservative leader Andrew RT Davies says the bill will 'clear the murky waters of Welsh devolution and deliver a stronger settlement that’s fit to stand the test of time.'
For the sake of Wales, it’s absolutely crucial that Labour’s First Minister backs this draft Bill and acknowledges the hugely positive benefits it will bring. I applaud the hard work of the Secretary of State for Wales. Now it’s time for the Welsh Labour government to get on with the task in hand. The focus should now switch to how we use these powers and how we will improve the NHS, boost economic growth and ensure our children are getting the education they deserve.
Nearly a decade ago the then Welsh Secretary Peter Hain declared that his Government of Wales Act 'settled the constitutional argument in Wales for generations to come.'
Everything that happened in Welsh politics since then seemed designed to disprove that.
His successor's been more circumspect and only said that he hopes politicians in Wales can move on from focussing on devolution.
The level of disagreement and the fact of a Welsh election next May could make that a forlorn hope.
At the very least there'll be a lot more talking to be done between now and February.