Alex Salmond and other SNP politicians had to be coached like children to stop them being negative during the last Scottish election, one of the first minister’s senior aides has revealed.

In one “game”, MSPs were given bags of pennies, then forced to hand over a penny each time they moaned and said something bad about a rival.

Brian Adam, the SNP’s chief whip at Holyrood, said that Salmond found changing his behaviour a “major challenge”, as his instinct is to attack opponents with stinging one-liners.

“He is not known as Smart Alec for no reason,” he told a group of American students.

Adam also admitted that the SNP might not have won in 2007 without calling itself “Alex Salmond for First Minister” on the regional ballot paper and coming first in alphabetical order.

The “voter management strategy” was thought to have given the party a 1% edge.

“Had it been ‘Scottish National Party’ we might have struggled,” he revealed.

The name change will not be allowed in 2011.

The emergence of the remarks comes as the SNP holds an internal debate on whether to return to negative campaigning in the wake of its defeat in the Glasgow North East by-election.

At last month’s party conference in Inverness, former leader Gordon Wilson said the SNP had to learn from Labour’s use of negative campaigning and be more “streetwise”.

After being out-polled three-to-one by labour in Glasgow North East, SNP activists have also been urging the party hierarchy to go negative.

“We can’t just sit back and take all the knocks and lies and criticism and hope people don’t take that on board. We have to fight fire with fire sometimes,” said one of those at the heart of SNP’s Glasgow North East campaign.

The chief whip’s comments were made in a talk at the Hinckley Institute of Politics at the University of Utah in the US in October 2007, a recording of which is now on the internet.

Adam, a member of the Church of Jesus Christ of Latter-Day Saints, delivered the same lecture on Scotland and Independence at the Mormon Brigham Young University in the state.

In his Utah talk, Adam described how the SNP instinct to attack was muzzled, as it ditched negative campaigning completely in favour of “hope and aspiration”.

He said: “We all had coaching. I remember going at the beginning of 2007 and sitting round the table as many other MSPs and hopeful candidates [did].

“We were all presented with a bag of pennies. Every time we said anything negative we had to put a penny in the middle of the table.

“This was to stop us saying negative things. It was a major change in approach, not just for the party, but for the party leader, who has a wonderful line in put-downs.

“He is not known as Smart Alec for no reason. He is a very very able politician ... but he had to change the way, not only [that] he presented himself, but the way he behaved, and it’s been a major challenge for him. He’s continued to do it post-election, and it’s actually worked.”

Adam described Salmond as a charismatic but divisive figure. “People either love him or they hate him.”

Gavin Brown, the Tory Lothians MSP, said the recording gave a new twist to the SNP’s old “Penny for Scotland” slogan.

“The truth is stranger than fiction. I wonder if they finished this course with a dance-off and a bush-tucker trial? I’d like to say more, but I don’t have any change in my pocket just now.”

John Park MSP, Scottish Labour’s campaigns and elections spokesman, said: “This is a startling admission from the SNP chief whip.

“It confirms that the SNP are the nasty party of Scottish politics. Their first instinct is always to be negative.”

An SNP spokesman said of the pennies game: “Labour certainly couldn’t afford to do that – it would cost them a fortune. Virtually everything they say is a negative attack on the SNP and Scotland’s potential – they are still sore because we won the election.

“The SNP’s entire goal is positive – engaging people in a process of Scotland becoming an equal and independent country.”