Sir David Murray has criticised the Scottish Government for ‘waste in projects’ and warned its spending is so unsustainable it is effectively ‘trading insolvently’.

The former Rangers chairman and businessman has not pledged any allegiance to a political party, but has been vocal about how the current SNP administration’s decisions impact business.

Sir David formed Murray International Metals Limited by the age of 23 and is currently the chairman of Murray Capital, a private investment company which is wholly owned by the Murray family.

It invests primarily in traditional economy businesses, with a preference for industrial sectors including manufacturing, engineering and oil and gas.

With the Holyrood election next week, he said of the state of affairs north of the Border: ‘For every £100 we take in in tax, we’re spending £120. We’ve got nearly a 12 per cent GDP deficit. It’s unsustainable. If we’re a business we’re trading insolvently, we can’t go on like this.

‘My main gripe is the waste in projects. When I was in Glasgow last week, I took the car past the new Barlinnie [prison] getting built. Already it’s going to be more than double the price, and already it’s not big enough.

‘Then I carried through to Airdrie-Coatbridge and the site of the new Monklands hospital, which I’m told if it’s finished for 2033 it could be £2billion. I do not understand.

‘We seem to make the same mistakes again and again. Where’s the discipline in building projects?

‘The Aberdeen bypass, the Aberdeen hospital, the Sick Kids in Edinburgh – when they’re building it, halfway through they realise (it’s) not the right filters in the system.

‘Surely somebody must be held responsible. These are massive projects which are not being controlled properly.’

Ahead of the election, the Scottish Greens have pledged to introduce a 10:1 pay ratio for any company or organisation receiving significant funding or contracts from the Scottish government.

This would be added to the conditionality of grants and contracts and mean the highest-paid employee at an organisation could not earn more than 10 times the salary of the lowest-paid worker.

The party has said it would be a wage cap on executive pay in order to distribute wealth.

But Sir David warned a cap on wages would put ‘a cap on ambition’.

He said: ‘I also think, unfortunately, some politicians… sneer at business people as if we’ve done something wrong to build a business to make money. There’s nothing to be ashamed about making money, as long as you do it within the rules along the way.

‘But I don’t think we encourage entrepreneurship. I don’t think we welcome enough business people, when you’re getting top business people going on radio shows and saying, “If we keep shaking the tree, there’ll be no apples to fall”.

‘You can’t keep going and going and going, there’ll be no money. I saw recently one of the politicians wants to put a cap on wages. Well, you might as well put a cap on ambition. Where’s the ambition?’

Sir David released his book Mettle last year which became a bestseller, with the paperback due out on May 9, two days after Scots go to the polls.

All the proceeds of his book are going to the Erskine Veterans Charity which he has supported for a long time.

He said: ‘When I first became an amputee many, many years ago, and I was involved in basketball, it was always a Thistle basketball club who came from people who were at the Erskine hospital.

‘So for 40 years, I’ve known of the hospital. It’s been through our foundation, we have a Murray foundation. One of the constant contributions we make is to the Erskine hospital.

‘If you look at and read about what they do, they help a lot of people.’