SNP leader Alex Salmond mooted his latest bid to win working-class support for independence on Saturday with a pledge to inflation-proof the minimum wage.

But trade unionists quickly pointed out the Scottish First Minister had stopped short of committing workers to a living wage.

Mr Salmond pledged to tackle his nation's cost-of-living crisis with a Fair Work Commission if there's a Yes vote next year.

Around 70,000 workers in Scotland are paid the minimum wage of £6.31.

But that 1.9 per cent increase falls far below inflation of between 2.8 and 3.2 per cent.

Mr Salmond told delegates at the party's national conference in Perth that it had been nearly a decade since the minimum wage had risen in line with inflation.

But the SNP would commit itself to a minimum wage that "rises - at the very least - in line with inflation.

"Never again will wages of the lowest paid in Scotland fail to keep up with the cost of living," he claimed.

But Mr Salmond carefully avoided a commitment to the living wage - the amount a person needs to earn to comfortably meet their basic needs, currently calculated at £7.45 an hour in Scotland.

Instead the Scottish government would charge the Poverty Alliance charity network with "accrediting" employers that paid a living wage.

Public-sector union Unison campaigns officer Dave Watson said there was a "very clear distinction" between a living wage and the First Minister's pledge.

Mr Watson - who has contributed to the Red Paper Collective's effort to inject class politics into the independence debate - said Holyrood had "done well" to guarantee the living wage for public-sector workers.

But the minimum wage should be nothing less, he said.

"Indeed, the hint is in the names.

"A living wage doesn't have to be an aspiration," he said.

Scottish Labour deputy leader Anas Sarwar dismissed the pledge as "empty promises about an imagined world after independence."

"Scotland remains on pause while the nationalists dream up goodies for the referendum campaign that they know they won't have to deliver on," he said.