British Prime Minister David Cameron during an election campaign stop...

British Prime Minister David Cameron during an election campaign stop at Harrison & Hetherington Livestock Mart in Carlisle, England on Wednesday, May 6, 2015. Credit: EPA / STR

Thursday's election in Britain is, by general agreement, one of the most important in recent history. At stake is Britain's fragile economy, its place in Europe and perhaps the future of the union itself. So why has the campaign been so petty and dispiriting? Over the past six weeks, when political leaders have met the public, there's been evidence time and again of people's utter lack of trust in what politicians from the established parties have to say, and in their ability to bring change. The politicians have responded to type, resorting to name calling and transparent last-minute ploys to buy votes.

Really, how did Labour leader Ed Miliband think that a giant limestone tablet with his campaign promises literally etched in stone would persuade voters to believe in him, rather than laugh at him? In a sense, it's a tribute to Britain's electorate that all this heat and noise has failed to move the opinion polls any significant distance since the campaign began. Except in Scotland, where the Scottish National Party looks set to deliver a huge shock to the British political system.

If I were a Scot, I'd be sorely tempted to vote for the SNP too. Not because I think it would be good for either Scotland or Britain to break up the union. Nor because I like the party's 1970s brand of socialistic economic policies. I'd be tempted because the SNP seems driven and different. These are the same qualities that are carrying upstart parties to prominence across Europe.

After a morning spent with Carol Monaghan, the SNP candidate to represent a gritty Glasgow constituency behind the Clyde dockyards, it became clear that many of those planning to vote for the SNP feel the same way.

A surprising number had voted against independence in last year's referendum, in what they said were "head over heart" decisions, because they thought Scotland wasn't ready. Many said they were supporting the SNP for the first time in a U.K. election -- hardly a surprise given that, in 2010, the SNP candidate got just 15 percent of the vote, to Labour's 54 percent. On Thursday, Monaghan is polling ahead of her Labour rival in a tight race.

As she walked through Glasgow's Partick district and stopped passers-by, about half were already wearing yellow SNP badges. They greeted Monaghan as though they were all part of the same happy conspiracy. The other half looked away.

Even many of the SNP's candidates are new to the party. Monaghan, 42, a high school physics teacher and mother of three, became a party official only after the referendum. No one is more astonished than she -- or more apprehensive -- at the thought that she may soon be heading to London as a member of Parliament.

Monaghan hates Prime Minister's Questions, the weekly parliamentary ritual in which MPs grill the prime minister, bray and hurl insults across the aisle (a macho affair that achieves nothing, she said). She also dislikes "showmanship" in politics -- but she's clear about what her job would be.

"We're going to be pushing Scottish issues 100 percent," Monaghan said. If elected, she plans to spend time at home as much as she can, not only because her family will stay in Glasgow but because "part of the problem with representation we've had in the past is that MPs got comfortable in London and forgot who they were working for." This is the paradox of the SNP that unsettles its opponents, and understandably so. To the extent that the party's British MPs do their jobs well and deliver for Scotland, they will also undermine the case for secession (why kill the union if it's working?). But to the extent that they compromise to be constructive, they risk losing the support of diehard independence advocates. So they have an apparent incentive to make Britain as dysfunctional as possible.

"No, I think that's a win-win for us," Monaghan says. "If we succeed in getting good deals for Scotland, that improves the lives of the people here. And the flip side is that people will also then get comfortable with the idea of Scottish representatives being able to deliver," thus improving the case that Scotland is ready to run itself.

Having spent the 1990s living first in the Balkans and then the former Soviet Union, I'm suspicious of nationalism as an organized political force and can't bring myself to welcome it. And the more success the SNP has in riding Scots nationalism to a repeat referendum, the more it will trigger a nationalist response in England.

Yet for Scots, the freshness of having teachers and oncologists go to Westminster with a mandate to aggressively and exclusively represent their interests -- rather than career politicians from the two old London-based mainstream parties -- is clearly attractive. No wonder SNP leader Nicola Sturgeon -- whom the Daily Mail newspaper has called the most dangerous woman in Britain -- is the most popular party chief, not just in Scotland but across Britain. (Her net rating is +33, compared with +7 for Cameron and -8 for Miliband.) The English, it seems, are also lusting for the sense of freshness and purpose that the SNP projects, and that their own political parties have so dismally failed to provide -- even if they don't like the SNP's particular, separatist purpose one bit.

Marc Champion writes editorials on international affairs for Bloomberg View.

Newsday LogoSUBSCRIBEUnlimited Digital AccessOnly 25¢for 5 months