Former prime minister Gordon Brown’s blueprint for the future of the UK will provide a "safer" and "more radical" alternative to Scottish independence.
Shadow Scottish secretary Ian Murray will tell delegates at the continuing Labour Party conference in Liverpool the document is almost complete and will be launched "in the coming months".
The Commission on the Future of the UK was set up to ensure “it works for every part of the country,” the shadow minister will say.
Mr Murray will make the comments while stressing politics in Scotland "can't keep being about the false binary choice of separation versus the status quo".
"It will not just try to convince Scotland to stay, but to make Britain such a good place to be that everyone, in all corners of our country, will want to be part of it," he will say.
"And in doing so, it will set out both a safer and more radical offer for change than the risk of independence ― the chance for a fairer, more secure, more respected Scotland within a reformed and modern United Kingdom."
The Scottish National Party wants to call a second Scottish independence referendum in 2023. However, the UK government says the question has been settled for a generation, arguing that it alone has the power to sanction such a vote.
A previous vote on independence in 2014 resulted in 2,001,926 voting against it and 1,617,989 voting in favour.
But eight years on, there are now ominous signs for the future of the union.
A poll carried on behalf of The National revealed fewer than one in three Britons believe Scotland will still be part of the UK by 2050.
The finding, released on Monday, showed even the patriotic fervour of the mourning period for Queen Elizabeth II did not convince Britain that its destiny is to stay together.
Asked about Scotland, only 31 per cent said it would still be part of the union by mid-century, while 48 per cent said it would not.
In other findings, the state-of-the-nation survey by Deltapoll for The National also revealed a distinct lack of enthusiasm for Brexit. This comes more than two years after the UK left the EU, a move that changed the dynamics of the Scottish independence debate.
A narrow majority of Britons saw Brexit as a bad thing and 46 per cent said it had gone worse than they expected. This compared with only 19 per cent, who were pleasantly surprised.
Reports have suggested Labour’s Commission on the Future of the UK may also include the abolition of the Lords, something the opposition party has previously raised. The SNP has called it "Broon's Brigadoon", claiming it was a plan that "magically emerges from the mists, before vanishing as quickly as it appeared".
"Labour has been promising to abolish the Lords for the past 112 years but, despite having been in government six times since for a total of 33 years, it has never come close to honouring that promise," SNP deputy leader Keith Brown said.
"There are Disney films more believable than Broon's Brigadoon."
