ONE of Nicola Sturgeon’s most significant acts as SNP leader was putting a former Holyrood colleague in charge of repairing her predecessor’s flawed economic case for independence.

The Yes side ran a ground-breaking campaign in the 2014 referendum and inspired a new generation to get involved in politics, but the independence side lost when it came to the argument on the economy.

On currency, the deficit, pensions, and start-up costs, floating voters were highly sceptical of Alex Salmond’s White Paper and delivered a ten point win for No.

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Sturgeon set up the Growth Commission in September 2016 to rethink the independence argument and, to this end, she turned to one of her party’s leading modernisers to chair the body.

Andrew Wilson - for those in the Yes movement with short memories - was a first-term MSP who tried, unsuccessfully, to broaden the SNP’s appeal beyond Nationalist voters.

In 1999, much to the annoyance of some of his colleagues, he urged his party to reach out to voters who feel British.

"Many aspects of what we understand as Britain and British institutions will remain with independence and that is nothing for us to feel threatened by,” he argued. Three years later, he called on the Tartan Army to support England at the World Cup.

His reward was to get bumped so far down the Central Scotland List that he was effectively deselected as an MSP. He secured a senior post at the Royal Bank of Scotland – not a great look these days – and is now a partner in a communications and lobbying firm.

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Wilson’s appointment was notable because he is a centrist on economics, not left-wing. Although a Nationalist on the constitution, he has New Labour instincts on the economy, believing that redistributing the proceeds of growth is a more sensible strategy than putting up tax rates. Sturgeon is well aware of her colleague’s outlook.

The problem for the SNP leader is that a sizeable chunk of the Yes movement – many of her own members, the Greens, the SSP and RISE – want a shift to the left. Mhairi Black, a party MP, spoke for many on her own side last week when she said she “hated” the White Paper. For her, it was like, “Union diet, like Diet Coke almost".

This eclectic coalition of radicals is growing increasingly frustrated by what they regard as Sturgeon’s timidity in government and the lack of a timetable for a second referendum. They believe the rebooted economic case for independence should challenge capitalism, rather than tweak it.

Revealed: SNP's new blueprint for independence

Wilson’s Commission findings will test the unity of the independence movement. New Zealand, which is the body’s preferred model, is a market-based economy and not a left-wing nirvana. The Commission, according to one well-placed source, is against austerity but will not promise “jam tomorrow”.

Tensions are clearly visible on the strategy for a new vote on independence, but the bigger divide may be on the sort of economy activists will be fighting for during any future referendum campaign.