Gordon Brown, in pole position in the event of a no vote to be hailed as the man who saved the union, has crafted a detailed plan for a post-referendum constitutional settlement in the UK, including a new role for an elected House of Lords as an arbiter in disputes between the four nations.
Brown is likely to get a prominent role in any debate following a no vote and has served notice that he intends to lead a major Commons debate on the future of the union when the party conference season is over.
He wants the entrenchment of the Scottish parliament, a codification of the purpose of the UK and a power-sharing partnership that he describes as home rule within the UK.
Until two weeks ago his plans might have quickly gathered dust, but the sudden transformation in his reputation from a failed prime minister to a visionary has given him a renewed influence.
David Cameron, for instance, has admitted he has been in frequent contact with Brown, leaning on his advice about how best to prevent a haemorrhage of Labour votes to yes. It has been obvious that the two joint devolution initiatives made in the last few days by the three Westminster party leaders were heavily influenced by Brown's thinking.
Many of Brown's ideas were set out in his summer book My Scotland, Our Britain.
Although some of his thinking will be anathema to Conservatives, much of it has been embraced by Nick Clegg and Cameron. The two party leaders have accepted his argument that "voters had a right to see the likely devolution reforms mapped out and to have them on the table before they vote in the referendum – enabling them to judge the merits of renewing the union versus the merits of ending it". No such clear devolution offer, or timetable, was on the table until Brown intervened.
His plan includes a statement of purpose for the UK similar to the US declaration of independence, including a commitment to provide security and opportunity for all. He also wants the Scottish parliament recognised as permanent and indissoluble. The same permanence, he suggests, could be conferred on the assemblies in Wales and Northern Ireland if there is consent from their representative bodies.
This blueprint includes an abandonment of the settlement in the 1998 Scotland Act which "held to the orthodoxy that Westminster is sovereign and that power devolved is power retained". He argues that, in reality, in its devolved matters the Scottish parliament now has autonomy and this should be reflected in an amendment.
He also proposes therevenue the UK parliament should raise should cover non-devolved services, with the revenue the Scottish parliament raises covering devolved issues such as crime, transport and housing. As a result there would be scope for devolved taxation to raise 40% of the Scottish parliament's expenditure.
He then argues if the UK parliament continues to have a role in equalising resources across the UK – through the Barnett formula – and is to maintain responsibility for welfare, social security, defence, macro-economic policy and foreign affairs, the Westminster parliament should have full representation by UK members, including from Scotland.
He also accepts the need to acknowledge English views within the current UK parliament by having an English-only stage for English legislation in the Commons, even if the final decision on a proposal rested with all MPs.
Finally, he suggests the Lords could become an elected senate and be more representative of the regions and nations. It might also be able to block legislation for two years if proposed laws meet such strong opposition in one part of the country that it threatens the unity of the whole.
The plan has many shortcomings, including saying little about devolving powers within English cities or regions, but if Scotland votes no on Friday, Brown will have earned the right for his ideas to be heard with the kind of respect he rarely drew in his time at No 10.
guardian.co.uk © Guardian News and Media Limited 2010