Senior Coalition sources claim the only question left is how small the Yes vote will be on September 18, 2014.
They claim any narrowing of the polls between now and then will be because of "protest votes", not any genuine increase in support for Scotland leaving the UK.
The comments will be met by derision from the SNP, Yes Scotland and the Scottish Government, who insist there is still a long way to go before the argument is settled.
They said that the UK Government's chief campaign co-ordinator was "staggered" by the lack of detail coming from the Scottish Government.
A Whitehall insider likened the battle to "professionals versus amateurs".
The SNP has accused the UK Government and high-profile ministers including Mr Osborne, of "scaremongering" over independence.
The Chancellor chairs the Coalition's cabinet committee on Scotland, which co-ordinates its push against independence.