In a potentially significant move, Labour MSPs and party researchers will be drilled in the Common Weal concept by the left-wing Jimmy Reid Foundation at Holyrood next month.
As the Common Weal vision includes a greatly expanded welfare state with universal public services, the development appears to signal a softening of Lamont's previous hard line on restricting or ending some universal services because Scotland could not be "the only something for nothing country in the world".
That remark, delivered in a speech a year ago to the fury of many in her own party, has been used ever since by the SNP to accuse Lamont of wanting to end universal services such as free prescriptions, university tuition, personal care for the elderly and concessionary travel.
The Common Weal concept, which has rapidly gathered support within the SNP and Yes Scotland campaign since its launch in the spring, advocates reshaping the Scottish economy in order to create a wealthier, less divided society.
Rejecting the UK's market-led economic and social model, which it says traps people in low-pay, low-skill jobs, it argues that Scotland could import proven policies from Norway, Finland, Sweden, Denmark and Germany. A central element is an expanded welfare state with cradle-to-the-grave public services paid for through an overall higher tax take, with the aim of creating a less divided society.
Common Weal also advocates more state ownership of infrastructure and assets, such as renewable energy, and state lending to Scottish firms to help foster high-skill, high-pay jobs in a diverse economy which is no longer slavishly reliant on banks and financial services.
The Church of Scotland has formed a working group to examine the idea, and the SNP conference will debate it in three weeks' time.
Until now, Common Weal has drawn its support largely from the pro-independence parties, as independence would offer the maximum scope for economic and social reform. However, the academics and economists behind Common Weal have always said some aspects could be applied under devolution, making it potentially attractive to Labour too.
In his speech to the UK Labour conference last week, party leader Ed Miliband illustrated potential areas of overlap when he denounced the "race to the bottom" on work and pay, announced plans for a massive housebuilding programme and confronted the privatised energy companies.
After the Reid Foundation approached Labour about a possible briefing, it was Lamont personally who took up their offer. Labour head of policy Hazel Maciver told the Foundation her boss thought Common Weal "might be an interesting discussion" for her 37 MSPs.
It is understood the chairman of Scottish Labour, Jackson Cullinane, who is also the regional political officer for trade union Unite, had been urging the party to give Common Weal a fair hearing.
Robin McAlpine, director of the Reid Foundation, will deliver the hour-long session on October 29.
He said: "We very much hope that we can develop a cross-party consensus on a Common Weal approach to Scotland, whatever the constitutional outcome next year.
"I'm delighted to have been invited to talk to the Labour group of MSPs and it bodes well for Scotland's future if we can build a consensus on delivering a fresh start for Scots."
A Scottish Labour spokesman said: "We identify with many of the values that inform the work of the Common Weal and are happy to hear, discuss and debate good ideas that will make Scotland a better, fairer place from any organisation."
Scottish Conservative enterprise spokesman Murdo Fraser said: "It now seems it's not just the SNP lurching to the left, and that Labour are following suit. I can't imagine the taxpaying Scottish electorate nor the business community relishing the prospect of such high-tax, left-wing policies being foisted upon them. This is bad news for a dynamic and enterprising Scotland."