The Coalition's top economists have spent months number-crunching the Scottish Government's White Paper and have highlighted what UK Government Ministers believe are glaring gaps in its numbers and an attempt to mislead voters.
But rather than present what the financial costs of independence would be to Scottish households, the Treasury will seek to present its findings in a more positive light, showing what the fiscal benefit of sticking with the UK will be; the so-called Union dividend.
In its analysis, the Treasury has highlighted what it regards as the Scottish Government's flawed arithmetic on boosting childcare, noting it is based on there being 21,000 more mothers moving into work than there are currently out of work in Scotland.
Last November, the SNP administration announced 1140 hours of free childcare per year for children aged one to school age. This, it was argued, would mean, as mothers joined or returned to the workplace, an increase in the workforce of 6% or an additional 104,000 women getting jobs with a consequent £700m in extra tax revenue.
But the Treasury pointed out data showed 83,000 women were unemployed in Scotland, meaning there was a shortfall of 21,000. "The Scottish Government's numbers simply don't add up," claimed one analyst.
Last night, Danny Alexander, the Chief Secretary to the Treasury, said: "This is typical of the Nationalist elite, who think they can con voters by inventing mothers that don't exist and then assume they will all get back into work." He added: "They will say anything, no matter how far-fetched to get their way."
More Treasury analysis also showed that by 2035/36 Scotland would need almost an extra 500,000 migrants - a population the size of Edinburgh - to achieve the same balance of pensioners to working-age adults as in the UK given Scotland's population is set to age more rapidly compared to the country as a whole.
As part of the UK, net annual migration to Scotland of 7000 has been assumed in the Treasury calculations, but this would have to increase to 24,000 under independence to achieve the same dependency ratio.
"To get the demographics simply to match the UK, Scotland would have to go up to the 'high migration scenario', which is 24,000 people a year net, so that's more than tripling in migration relative to Scotland within the UK," said one Treasury analyst.
A Scottish Government spokesman said: "Net migration to Scotland is already more than 10,000 a year and independence will allow us to have a flexible policy to suit our economic needs."