The number of Senedd members is set to increase from 60 to 96 and the way they would be elected drastically changed under new proposals put forward jointly by the First Minister and the leader of Plaid Cymru.
If accepted, the changes would be introduced in time for the next Senedd election in 2026.
Supporters of changes have long argued that there are not enough MSs to scrutinise Welsh Government properly, once government ministers and presiding officers are taken out of the equation.
These proposals come as part of the cooperation agreement reached between Labour and Plaid Cymru, who are working together to deliver some aspects of Welsh Government, although Plaid has not entered into a coalition government.
It is not yet clear how much the change would cost. The Senedd Commission, which runs the Welsh parliament, estimates that an extra 30 members would cost between £11.7m and £12.9m.
That figure is not only for members' salaries, it would also include pay for Senedd staff, running of elections and the upkeep of the parliament building and associated offices.
The total running cost for the Senedd in 2021/22 is due to be £62.9m.
That amount is agreed by Labour, Plaid Cymru and the Conservatives who jointly run the Senedd Commission.
The money comes from the overall budget for the Welsh Government which in turn comes from a mixture of direct UK Government funding and money raised by some income tax and other Welsh taxes.
The leaders, Mark Drakeford and Adam Price, have set out their preferred options in a letter to the committee looking into Senedd reform.
They want to change the way Senedd members are elected.
Currently 40 are elected for single-person constituencies by the familiar ‘first-past-the-post’ system which sees whoever wins most votes taking the seat.
A further 20 MSs are chosen to represent 5 regions in a second vote which takes place at the same time as the constituency vote.
You may remember when you voted in 2021 having a second ballot paper which you used to list your preferred political parties.
Those votes are added up and divided out amongst the parties in a system that is aimed at better reflecting the share of vote that each party receives
Under the new proposals, there will be 32 constituencies for the Senedd. These will be based on the 32 new constituencies for the UK Parliament which are currently being drawn up by the Boundary Commission for Wales.
They would be paired to make 16 regions which would return six members each.
The lists the parties would put forward for each region would be legally required to meet gender quotas.
What happens next is that these proposals are considered by the cross-party committee on Senedd reform which will publish its report at the end of May.
That will then be debated in the chamber and voted on by MSs.
Any big change like this has to be backed by a ‘super-majority’ made up of two-thirds of Senedd Members.
First Minister for Wales Mark Drakeford said: "The case for Senedd reform has been made. We now need to get on with the hard work to create a modern Senedd, which reflects the Wales we live in today. A Parliament that truly works for Wales."
Adam Price, leader of Plaid Cymru, said: "These reforms will lay the foundations for a stronger Welsh democracy and a fairer, more representative Senedd that will look entirely different to the outdated political system at Westminster.
"A stronger, more diverse, more representative Senedd will have a greater capacity to perform its primary purpose of making a positive difference to the lives of the people of Wales."
The Welsh Conservatives are opposed to any increase and will vote against but between them Labour and Plaid Cymru have enough members to ensure the changes are supported.
The leader of the Welsh Conservatives has criticised the proposals as a waste of money.
Andrew RT Davies tweeted, "1 in 5 people in Wales are on a waiting list. Young people in Wales can only dream of getting on the housing ladder. Wages in Wales are the worst in the UK. Labour’s priority? More politicians in Cardiff Bay."
Welsh Conservative MS Darren Millar has resigned from the Senedd reform group after Labour and Plaid’s announcement, calling it a "completely out of order stunt".
The Liberal Democrats support reform but think these plans will not deliver what is needed and are predicting the changes will be proven not to be fit for purpose as soon as they are introduced.
Welsh Lib Dem leader Jane Dodds said, "The proposed constituency map will mean nothing to communities and we will still be lumbered with a voting system that fails to ensure that votes match seats. Plaid Cymru appeared to have abandoned their commitment to STV [Single Transferable Vote].
"In a scramble to make an announcement, Plaid Cymru and Labour have ensured that the debate about whether the Senedd is fit for purpose will start no sooner than these proposals are brought into law."