'I had thought I would be coming to a wake ... instead the party is ready to go forward'

He dropped by the SNP's post-referendum "party" next to the Scottish Parliament. As he left that miserable affair, he thought things couldn't get much worse.

Then a car decked in Union Jacks roared up, and a group of jubilant No supporters inside started singing Rule Britannia.

"I thought the party was going to be flat on its back after the result," said Munn, one of 1200 delegates at the SNP's Perth conference this weekend. "I was warning people it was going to be really tough for a while. Nothing prepared me for what happened the following week, when the membership went through the roof."

MSP Christine Grahame shared Munn's foreboding. At her local count in Midlothian, she said she felt "sick to my stomach".

"I had no idea I would be coming to this conference with a spring in my step and with the SNP having 60,000 extra members," she said.

"I had thought I would be coming here to a wake. Instead the party is ready to go forward."

Tales of similar rollercoaster emotions were commonplace among activists in Perth.

Despite political lore predicting a period of introspection and infighting for a party after a big defeat, the SNP has found itself on an unprecedented high.

Activist were gutted by the No vote, but the blues never had time to take hold. Instead a recruitment surge, coupled with the bonding experience of the referendum and the knowledge that 45% of the country was with it, let the SNP snap out of its funk.

And although the party lost one popular leader because of the referendum, it has now gained another.

Added to which, the main opposition in Scotland is in panic as the General Election looms, and increasingly divided because of its own leadership turnover.

It is as if the referendum has been the making of the SNP, elevating it from political party to cornerstone of a national movement.

Defending his rocky leadership of Labour last week, Ed Miliband quoted Nietzsche: "That which does not kill us makes us stronger."

It may or may not prove appropriate to Miliband, but it could almost be the SNP's new motto.

Since the No vote, SNP ­membership has gone from 25,000 to 85,000, making it the third-­largest party in the UK, twice the size of the UK LibDems.

One in 50 adults in Scotland is now an SNP member, the equivalent of a UK-wide party having a million members.

In his valedictory speech to conference on Friday, Alex Salmond set the SNP a membership target of 100,000 before May's General Election.

If that target is hit, the old guard will be outnumbered three to one by the new intake.

As Nicola Sturgeon said on Friday: "We are not the same party we were on the September 17."

One senior LibDem joked the new recruits would soon become "the tail wagging the dog".

He was wrong - they are the dog.

Which poses a very big question for the SNP: who are these people and what do they want?

Stephen Gethins, a former special adviser to Salmond, said the party is still finding out.

"The SNP has got 60,000 new members. I don't think you can put 60,000 people into a box and say this is what they're like. Every branch is engaging with the new members. It's a big process."

Others have a hunch the new members are more aggressive, and want fast action on the constitution.

One SNP councillor said many new recruits want another vote: the campaign had "radicalised" them in a peaceful, democratic sense. "There's certainly a lot of talk about next time," added Munn. "People want to organise. That's the impression I get."

But the SNP's focus is currently on May, followed by the 2016 Holyrood election. Talk of a rapid referendum is downplayed by the leadership, who say the timing will be set by public demand and events, meaning they'll wait until the polls show they'll win.

In the meantime, the SNP want to harness the energy of their new members and direct it into the electoral cycle. For those used to energy rush of the referendum, that may not be as appealing.

The new intake, after all, could have joined the SNP before the referendum, to help their election efforts, but chose not to.

The question of when to hold the next referendum will hover over Sturgeon's leadership. She will need all her skill to manage - and dampen - expectations.

But for now Gethins says the SNP's challenges are ones other parties would give their eye teeth for. "To have a party that's grown four times over is unprecedented in modern European politics.

"This is a great conference to be at. It's fantastic to see people so involved in politics. The party is vibrant, it's energetic, it's motivated in a way I've never seen before."