ANAS Sarwar has ignited a fresh row over his family business, saying it doesn’t pay workers the real living wage promoted by Scottish Labour because it's only voluntary, not mandatory.

In a bruising BBC Radio Scotland interview, the party leadership candidate also defended sending his children to private school, saying his wife was partly responsible for the decision.

He said people should respect a decision made by a couple “in the privacy of their own home”, but admitted: “The fact is too many of our schools aren’t good enough in Scotland.”

At one point, an irritated Mr Sarwar criticised Good Morning Scotland presenter Gary Robertson, accusing him of focusing on personality issues rather than policy.

The SNP said Mr Sarwar was guilty of "appalling hypocrisy".

The encounter highlighted the baggage the centrist millionaire MSP brings to the leadership race, in which he is pitted against left-winger Richard Leonard, a former trade union official.

Mr Sarwar, 34, has been under fire for more than a week over employment practices at United Wholesale (Scotland) Ltd, one of the country’s largest cash and carry businesses.

The Glasgow MSP owns almost a quarter of the shares, worth an estimated £4.8m.

The Herald’s sister paper, the Sunday Herald, revealed 10 days ago that UWS pays staff less than the real living wage of £8.45 promoted by Scottish Labour.

It was recently recruiting staff at £7.50 an hour.

Mr Sarwar has also confirmed that UWS, despite being founded in 2001, has never had formal trade union recognition in place for its 250 staff - he says no union ever asked to set up a collective pay bargaining unit at the company.

On Radio Scotland, Mr Sarwar was asked whether his wealth and school choice made him one of the “few”, despite Jeremy Corbyn promising to stand up for “the many, not the few”.

He replied: “The reason I’m in the Labour party is because I don’t choose to opt out of politics. I choose to fight for equality, to fight for opportunity. That’s why I’m in the Labour party.”

Asked if the pay at UWS undermined his credibility and whether paying a real living wage “should start at home,” Mr Sarwar said: “The difference is I don’t support a voluntary real living wage. I support a mandatory real living wage. I don’t think it’s right that the market dictates what a fair day’s pay is, and that’s why I want it to be a compulsory policy.”

Asked how he expected to influence government policy if he couldn’t influence his family business, Mr Sarwar said: “One, I’m a minority shareholder in the company.

“Second, I have no role in the company. I’m not a director in the company. I have no say in how the company operates.

“But I have had assurances from the company that they do want to transition to a real living wage for all employees.

“They too have welcomed the fact that a Labour government would introduce a real living wage much quicker than the current UK government, meaning they’d be able to implement it quicker, and also so it’s compulsory on every company.

“I don’t care who the shareholder of any company is, I don’t care which company it is, I want every company to be mandated by the government to pay the real living wage and not use the market as the excuse.”

Mr Sarwar was also asked about sending his young sons to £10,000-a-year Hutchesons’ Grammar instead of a state primary school.

“Again, Gary, I would rather you focused on the policy,” he said.

Pressed on the matter, he went on: “It’s clear you only want to focus on policy with one candidate, not the other, which I think is unfortunate.

“But directly answering the question on that, that’s a decision that my wife and I took.

“That’s a decision we made as a couple. I’m sure people would respect decisions that are made by any couple in the privacy of their own home.

“What I would say is, the fact is too many of our schools aren’t good enough in Scotland.

Too many of our teachers aren’t getting the resources they need.

“We have 4000 fewer teachers in our school system [under the SNP]. That’s not acceptable. I want opportunity for all children, and that’s why we need to increase the tax rate.”

Earlier on the programme, Mr Leonard said he wanted more workers given state loans to help them buy out their employers.

He said: “I think working people should be given the option of buying the business they work in when it’s put up for sale or facing closure.

“That’s quite a mainstream idea in the rest of Europe, and that would in turn hand power to those creating the wealth to allow them to become the owners of the wealth. There would be some initial capital costs but it would be a loan that was repaid by the enterprise.”

The 55-year-old Central Scotland MSP also defended Labour’s plan to hike the basic rate of income tax from 20p to 21p in Scotland using Holyrood’s new fiscal powers.

In what appeared to be a sky dig at Mr Sarwar, he said: “We’ve had a decade of the SNP in power and we’re sitting here in a situation where in Scotland where the top 1 per cent of wealth owners own more wealth than whole of the bottom 50 per cent put together.

“That’s a profoundly unequal society and intolerable in my view.”

“I campaigned in the 1990s for a Scottish Parliament not just to create an institution, but to create an institution that would legislate differently from the Westminster parliament, but would also provide a bulwark against Tory fiscal policies.”

He was asked how Labour’s plan to increase the 45p rate of income tax to 50p would help pay for better services when fewer than 20,000 Scots earned over the £150,000 threshold.

He said: “We have set out our case that there should be an increase in the basic rate of taxation too, precisely to address the fact that there aren’t enough people in the higher earning bracket to make up for the huge shortfall which there is in funding for public services in Scotland as a result of Tory policies of austerity.”

SNP MSP Clare Haughey: “This is appalling hypocrisy which goes right to the heart of Anas Sarwar - and Labour’s - credibility.

“Mr Sarwar doesn’t think his family firm should pay staff fairly because it’s not legally compelled to do so.

Instead, he only supports the fake living wage of a Tory government hell-bent on eroding workers’ rights.

“How many workers are affected by this – and how much in total should they be due if Mr Sarwar’s firm had been paying them properly?

“While the SNP will always encourage employers to pay workers a wage which meets the real cost of living, it’s clear that Anas Sarwar’s focus is on profit for the few, not the many.”