The publicity offensive comes in the wake of the London Olympics, which buoyed the unionist cause.
Fired up by the pro-British mood the Games left in their wake – and also stung into action by a stream of events by the rival Yes Scotland movement – the Better Together team will campaign in all 59 Westminster constituencies in Scotland as part of a National Campaign weekend on August 25 and 26.
Volunteers from Labour, the LibDems and Tories are to receive "campaigns in a box" containing sign-up forms, banners, Saltires and Union flags, balloons and children's face paints in order to catch voters' attention at street stalls and fetes.
The aim is to distribute 100,000 leaflets setting out the case for retaining the Union. With the message "We love Scotland", the leaflets cover the shared history of the British Isles, including the pound, but also stress the danger of going it alone in a turbulent world economy.
"We don't need uncertainty, instability, and barriers for our businesses," they will say. "The UK is better placed than a separate Scotland or England to help our businesses find and win new orders across the world. In an uncertain economy, the UK is a source of strength for Scotland."
However, there are concerns among some volunteers that the weekend has been rushed to capitalise on the Olympic feelgood factor and that could result in the Unionist parties running separate stalls, undermining the whole concept of Better Together.
Volunteers were given just 10 days' notice through an email from campaign director Blair McDougall saying: "We want to kick this grassroots campaign into gear by having events not just in one or two towns, we want to bring Better Together to every town in Scotland. It is so important that we speak to people face to face about Independence."
Better Together bungled the announcement of the event on its Facebook page. This initially said there would be a "National Campaign Day" next Friday, then changed it to next Saturday, then changed it again to both Saturday and Sunday, then finally changed its name to the "National Campaign Weekend".
One Tory volunteer said the omens were not good: "This has come out of the blue. It seems to be a rush job. I've been given no details from them or my local [Conservative] association.
"It looks as if it's been cobbled together on the back of the Olympics. Better Together might also be getting nervous at all the stalls being run by Yes Scotland round the country."
Other would-be volunteers have left messages on Better Together's Facebook page, asking if anything is happening in their area.
Launched in June, Better Together is spearheaded by Labour and backed by the Tories and LibDems.
In recent weeks, its website has run a series of items explicitly linked to the Olympics, including an electronic Team GB calendar, and an article saying the Games "confirmed how much the rest of the UK values Scotland's contribution".
It concluded: "If, like us, you don't want the London 2012 team to be last Team GB, then join us."
McDougall said: "We are confident that if we can present people with the facts, then they will come to the conclusion that we are better together with the rest of the UK. Next weekend is the first step in that process. The event is significant as it is the first time since our launch that we have gone out to the country in such a large-scale, coordinated way."
An SNP spokesman said: "The Tory-led No campaign will not fool the people of Scotland – it is clearly as dysfunctional as their ridiculous idea that it is better for Scotland to leave all the key powers over the economy and welfare in the hands of the Tories at Westminster."
Meanwhile it has emerged Alex Salmond aims to hold face-to-face talks with Prime Minister David Cameron and Scottish Secretary Michael Moore in Edinburgh next month over the format of the 2014 referendum, and crucially whether there might be a second question on more powers for Holyrood short of independence.
Cameron has offered to make the vote legally watertight by granting Holyrood extra powers under a so-called Section 30 order, but on condition there is a simple Yes/No question on independence.
Salmond insists there should be no pre-conditions, and is keeping his options open. He recently said Scots had a "right" to vote on whether Edinburgh should have full tax-and-spending powers, also known as Devo Max.
SNP insiders say even if the Devo Max option is not on the ballot, it is useful to keep the idea alive as it draws voters toward independence.