EDINBURGH -- The two sides in Scotland's independence debate scrambled Tuesday to convert undecided voters, with just two days to go until a referendum on separation.
The pitch of the debate has grown increasingly shrill as both sides make their oft-repeated claims and promises with increasing urgency, and supporters square off at public appearances.
Labour Party leader Ed MIliband, who backs the anti-independence "Better Together" campaign, was surrounded by rival camps shouting "Vote Yes" and "Vote No" during a walkabout at an Edinburgh shopping centre.
Miliband said he understood that "passions run high," but he hoped the debate would be conducted "in a civilized way."
Thursday's referendum, in which more than 4.2 million people are registered to vote, is a high-stakes decision that could end a political union that has stood since 1707.
Anti-independence campaigners argue that separation could send the economy into a tailspin. The Yes side accuses its foes of scaremongering and says independence will give Scots political control and economic prosperity.
After a late poll surge for the pro-independence side, the No campaign is striving to persuade Scottish voters that they will gain more autonomy if they do not secede.
Prime Minister David Cameron, Miliband and Liberal Democrat chief Nick Clegg all signed a pledge published Tuesday in the Daily Record newspaper promising Scots "extensive new powers" -- including tax-raising authority -- if they remain part of the United Kingdom.
Labour Party politician Douglas Alexander said a No vote meant "faster, safer, better change for Scotland," while independence would bring "risks, uncertainties and costs."
"With just 48 hours to go, they can't even tell us what currency we'll be using," Alexander told No supporters in Edinburgh's financial district.
The pro-independence Scottish government says Scotland will continue to use the pound sterling, but the British government insists it won't agree to a currency union.
The Yes campaign says the promises of new powers are vague and reveal the No side's desperation.
"This last-minute desperate offer of nothing is not going to dissuade people in Scotland from the huge opportunity of taking Scotland's future into Scotland's hands this coming Thursday," First Minister Alex Salmond told the BBC.
Salmond has stressed that after a Yes vote, many things will not change, from the currency to the monarch, Queen Elizabeth II.
No campaigners have used increasingly stark language to claim a Yes vote would be irreversible.
On Tuesday Former Prime Minister Gordon Brown -- a Scot who commands considerable popular affection in the country -- said voting for independence would end "every single last remaining link that exists, the connections we have, with our friends, neighbours and relatives" in the rest of the U.K.
"This cannot be a trial separation," Brown told an audience in western Scotland. "This is bound to be a messy and expensive and costly and difficult divorce."
But Deputy First Minister Nicola Sturgeon said Scotland would "continue to be part of the family of nations that make up the British Isles."
"Those ties are not about politics, those ties are about people," she said.
Polls suggest the outcome will be close, and several hundred thousand voters who have yet to make up their minds could determine whether Scotland leaves its 307-year-old union with England.
For some voters, concerns about economic insecurity and job losses are a powerful reason to reject independence.
Property developer Alex Watts said international investors were putting Scottish projects and purchases on hold because of the uncertainty around the vote.
"What the property industry needs in Scotland is more certainty and stability," he said. "Why should we take the risk? Scotland is not the only place to invest in."
Others, though, say the negative campaign of politicians on the No side has driven them into the Yes camp.
"Rather than putting their own case for why we should stay together they're trying to scare us into not separating," said Mike Smith, who sells leather goods from a stall along Edinburgh's Royal Mile.
"If that's what they're doing now, what are they doing the rest of the time?"
