Yes or no? Race is on for Scotland's undecided voters.

On Monday, Scotland's pro-independence First Minister Alex Salmond and Alistair Darling, leader of the 'No' campaign, will face off in their final televised debate between the country's Sept. 18 referendum.

Scotland's long debate over whether the country should become independent has proved a bonanza for printers of bumper stickers, posters, balloons and even umbrellas.

Nationwide the words "Yes" and "No" can be found emblazoned on everything from street lights to shopping bags. Posters proclaiming "Proud to be Scots. Delighted to be United" and "Yes to a better, fairer Scotland" adorn the windows of homes sharing the same street.

On Monday, it's showdown time. Scotland's pro-independence First Minister Alex Salmond and Alistair Darling, leader of the "No" campaign, will face off in their last televised debate before the Sept. 18 referendum.

Both sides claimed victory when the two clashed Aug. 4 – and interest from outside Scotland was so high it caused the Internet platform streaming the event to crash. This time the 90-minute debate will be shown on the BBC across Britain, and on C-SPAN in the United States.

At stake is the support of thousands of voters who, despite a campaign lasting two years, have yet to make up their minds.

Up and down the country activists have held thousands of town hall meetings, coffee mornings in private homes, and passionate discussions in pubs, clubs, town squares and on public transport.

People who have never been involved in politics before have come together and created a truly grassroots national debate about a vote that could affect everything from Scotland's economy, passports, currency and military to its sense of national pride and its role in the European Union and other international organizations.

"Wherever you go somebody is talking about it," said Mairi Campbell, 38, a hairdresser from Glasgow who says she's definitely voting against independence.

"I used to spend a lot of my time talking to customers about whether they had a good holiday or were planning a night out. Now the conversation might start that way but ends up with something about the referendum and what it means," she said. "Almost everyone has an opinion and different reasons as to which way they will vote."

Politicians from both sides have toured Scotland's cities, towns and villages to address the public, often out in the open, distributing miniature flags — the blue and white Saltire of Scotland, or the red, white and blue of the Union Jack — while standing on modern equivalents of the corner soap box.

School halls have held question-and-answer sessions for students, reflecting the fact that, for the first time in Britain, 16- and 17-year-olds are being given the right to vote.

"This is the biggest grassroots campaign Scotland has seen and it has encouraged more people to engage and get involved with politics than at any point in my lifetime," said Robin McAlpine, 41, director of Common Weal, which was set up to promote the ideals of a fairer society.

On the pro-independence side stand more than 350 independent groups. Not one is centrally controlled, organized or funded.

The "No" campaign, which claims to have the support of the silent majority, has brought together a wide range of unionists from Labour and Conservative party members to socialists and members of the right-wing U.K. Independence Party.

Opinion polls suggest voters are narrowly divided on whether to break up Scotland's 307-year-old union with England or remain alongside the English, Welsh and Northern Irish inside the United Kingdom. In opinion polls the anti-independence side has maintained a consistent lead — but as many as a million undecided voters hold the balance.

Voter turnout in the referendum is expected to be high, possibly topping 80 percent. That would be the highest-ever figure in Scotland and much greater than the 50 percent who voted in Scotland's last parliamentary election.

Nighet Nasim Riaz, 46, a member of Scots Asians for Yes, said people are hoping to see the TV debaters maintain their civility.

"The last televised debate between Alex Salmond and Alistair Darling was not what people wanted to see: two middle-aged men having digs at each other," she said. "It's what you do in a playground. People want a bit more dignity and answers to questions that don't skirt around the issues."

But with a positive mood on the streets, both sides hope the debate will provide a final push to capture wavering voters.

"Whatever the outcome," Riaz said, "something fundamental has changed in the way people are now becoming engaged and taking an interest in politics."