He said the House of Commons would need to be balanced by a new upper house with equal representation from England, Wales and Northern Ireland.
Mr Jones said the system could be based on the Senate in the United States.
"You would have for example, a Parliament in London with about 550 MPs, 510 of whom would be from England. Well that's no good to us at all."
"There would need to be a fundamental rethink of the nature of the relationship between the three nations left within the UK in order to make sure that, what was then the UK, was a stable body where people felt that they had full representation."
But it seems 510 MPs from England and about 80 from Wales,Scotland and Northern Ireland is acceptable.
Surely a federal solution under Carwyn's criteria, would apply to the current position of the Nations of the UK as well as one in which Scotland had left?
Carwyn doesn't call for a English parliament but how could a federal structure work with the House of Commons being (as it is almost now) also a an English parliament ?
But what of Carwyn's second chamber? Does he propose an equal number of Senators from Wales,England and Northern Ireland say 150 from each or one in which there are say 200 English senators and 100 from the other two?
I can't see this being acceptable to English MPs or English voters who would never see English dominance diminished in even one of the Legislatures. Indeed I suspect that they would much prefer the complete break up of the UK rather than accept a Federal Solution (including one which Scotland was still part).
If I thought it would work, if the nations of the UK could exist in a Federal structure of equals then I would seriously consider it but the English Question is to complex .
Regional Government in England would not solve the problem. Wales is not a Region and if there was a Federal structure it ant of the UK legislatures should not be treated as a region like the South East of England.
Such a structure may work in England as an Independent country and I wish them well if they decide to do so. Though I would hope Cornwall's unique position would be taken into account and or perhaps they could join us eventually as Independent member of the European Union.If Luxembourg can be so can Cornwall).
In the meantime it is good to see the First Minister looking ahead but if he can't accept that Welsh Mps whether there are 40 or 30 are dominated in the Westminster Parliament at present and realise that Wales should have Legastive powers equal to Scotland even under the present Union how can he claim that a future UK without Scotlant will be detrimental to Wales?