THE Lang Toun isn't exactly a hubbub of political activity the day The Herald comes calling.

The big issues on the streets of Kirkcaldy are not who will succeed Gordon Brown as local MP, but local fireman Stevie McCrorie's irresistible ascent to winning The Voice talent show, and the closure of the town centre's Tesco supermarket.

But why are we here at all? Surely a Westminster seat bequeathed by a former Prime Minister and Chancellor, with a majority of more than 23,000 and a share of the vote of almost 65 per cent, must be a shoo-in for his Labour successor?

You would have thought so, but then along came Lord Ashcroft with his pesky polling and the extraordinary finding that a swing of more than 28 per cent to the SNP could take even this rock solid bastion away from Labour.

That poll, one of a series carried out by the peer in key Scottish seats, was incendiary. It had the Conservatives on just 7 per cent and the LibDems on a vanishingly small 3 per cent. But on the big head-to-head his poll had the SNP on an astounding 45 per cent to Labour's 39 per cent.

The Conservatives are fielding experienced candidate and local councillor Dave Dempsie, who is expected to shore up the Tory vote, but Callum Leslie of the Liberal Democrats and Jack Neill of Ukip will be fighting to save deposits and avoid the ignominy of last place.

To be clear, if Labour end up being defeated in a seat like Kirkcaldy and Cowdenbeath they are heading for electoral oblivion in Scotland. Fortunately for Labour, they have at least had a painless selection process producing a very presentable candidate.

Kenny Selbie, 33, is a Fifer and currently councillor for Kirkcaldy Central. He is a fine looking father of two young children, personable and can string words together without tripping himself up, having worked for central and local government in human resources, specialising in equalities issues.

In short, he is an excellent candidate who, handed the safest seat in Scotland, could once have considered himself short odds to succeed Brown as the area's MP and looked forward to decades at Westminster. And yet he finds himself swimming against a strong tide.

"When the Ashcroft poll was announced it just didn't chime with what we were experiencing on the doorsteps," he said over a pot of tea after a day in the council chamber. "What we are getting is a call to action, with the local party responding. It's all been very positive since then, although we are taking nothing for granted."

He also rebuts his opponents' claims that Labour will simply continue the Tory austerity programme, in line with a recent Commons vote. "There is anger and disillusion about the Tory cuts but people realise a Labour programme has to be costed.

"It's not a regular, day-to-day thing to have that austerity vote cast up. Social justice and inequality are issues which are dear to my heart."

His problem is not just an impressive opposing candidate exactly twice his age, but the formidable organisation behind him. The SNP's Roger Mullin was in a position to take time out from his academic career when he was adopted as candidate in January, making clear that he expected the seat to be fought with the intensity of a by-election. "We had put out more than 150,000 pieces of campaign literature and canvassed every single part of the constituency, and that was before the Ashcroft poll," he explains in the prominent campaign office on Kirkcaldy High Street.

While membership of the SNP has risen four-fold since the referendum last September, in this constituency it has risen six-fold and new card carriers bring a burst of enthusiasm. "We recently signed up our 600th member in Cowdenbeath, a 90-year-old D Day veteran. Labour used to think they could simply weigh the vote here but that's no longer the case."

This membership surge is why the office is eerily calm when The Herald visits, because in terms of stuffing envelopes and boxing up literature they are so far ahead of schedule. This vast army of enthusiastic new foot soldiers means he can afford to operate separate teams of party members to carry out the different campaigning functions - delivering leaflets, canvassing, promoting the cause on social media.

Where the two sides disagree is on the impact of Gordon Brown, who has been active in support of his successor. For Councillor Selbie this has been an unalloyed benefit, galvanising support, while his opponent is relaxed about the impact.

"Our impression is that every time Gordon Brown's picture appears or he comes out in support of the Labour candidate it serves to solidify the views of an aggrieved Yes voter," says Mr Mullin.

Who is right? We'll find out soon.