In recent months, the 'No' side has seen the Alistair Darling-led Better Together campaign rethink its approach and change its message to ‘No thanks’ and the emergence of alternative pro-UK campaigns such as Let’s Stay Together and Vote No Borders.
The 'Yes' campaign, led by umbrella organisation representing groups ranging from the Scottish National Party to local business-led Yes Scotland, has fallen behind in the polls.
"After a period of malaise the campaign to save the UK has regained its stride," said Interel managing partner and former special adviser to the secretary of state for Scotland George McGregor.
"It had a successful rebrand from ‘Better Together’ to ‘No Thanks’. The polls are decisively in its favour. Its endorsers are bigger hitters. And it has shifted its campaigning to the emotional – as well as rational – case for staying in the United Kingdom."
However, he predicted the Yes campaign could regain the upper hand: "It has an army of highly motivated activists who will seek to get out their vote and it will be hoping the Commonwealth Games will stir Scots to backing independence. It is going to be a nail-biting nine weeks and no one can be certain of the final outcome."
Ketchum MD of corporate and public affairs Jo-ann Robertson said an interesting development was the emergence of different campaigns on the No side in response to criticism of the Better Together campaign as overly negative.
"That’s what’s most interesting about the momentum. They are reaching out to different parts of the electorate."
She agreed that the No campaign was clearly ahead: "I wouldn’t underestimate [First Minister Alex] Salmond, but I think he has undermined himself. At the start of this year I would have said he would have taken the upper hand but now he’s doing more damage than good."