MORE than £200,000 was sunk into Scottish Labour’s toxic leadership race, it has emerged.

New declarations show losing centrist candidate Anas Sarwar received more than £150,000 in donations, with his family and its businesses the largest source of cash.

Richard Leonard, the victorious left-winger, was almost entirely funded by trade unions.

He received more than £64,000, almost half of it from the super union Unite, which is also the largest funder of the UK Labour party and a key supporter of Jeremy Corbyn.

The updated register of MSPs' interests at Holyrood shows Mr Sarwar received £20,000 from his mother Perveen and £10,000 from well-known Glasgow businessman Lord Willie Haughey.

He also received £41,000 from United Brands Ltd, a part of the family cash and carry business, United Wholesale (Scotland) Ltd, or UWS, which is run by his brother Asim.

Another UWS offshoot, United Tradeston Ltd, donated £2691 towards campaign office costs.

The Herald revealed earlier this month that Mr Sarwar also took £40,000 from a firm run by one of Asim’s business associates, Kasim Gulzar, and another £40,000 from a Scottish subsidiary of a company registered in the tax haven of the British Virgin Islands.

Of the £64,280 declared by Mr Leonard, £60,000 was from unions: Unite £30,000, GMB Scotland £12,000, Unison Scotland £9000, CWU £5000, and Usdaw and Aslef £2000 each.

Thompsons Solicitors donated £2130 worth of office space, and four individuals gave £2150 between them, including former Glasgow MP Maria Fyfe, who gave £350.

The contest was triggered by the sudden resignation of Kezia Dugdale in August.

Her departure after two years led to a poisonous contest between Mr Sarwar, a millionaire who sends his children to private school, and Mr Leonard, a former official with the GMB.

There were claims of vote rigging, ghost members and a left-wing plot against Ms Dugdale.

Then deputy leader, Alex Rowley, was secretly recorded saying he backed Mr Leonard, despite ostensibly being neutral, and later stepped aside after a former girlfriend made allegations about his conduct - he confirmed on Saturday he would not return as deputy.

Mr Sarwar also had to transfer his £5m stake in UWS into a trust for his children after it emerged the firm didn’t pay Labour’s living wage or have formal union recognition in place.

SNP MSP James Dornan said the donations were extraordinary given the messy contest.

He said: “It’s clear now why every comment Richard Leonard makes is about defending trade unions - he owes his position to their funding.

“I’m delighted the Sarwar family business was still able to support Anas, despite him cutting his ties. They must be doing well to throw good money after bad on such a poor product.”

The 2014 Scottish Labour leadership race, in which left-winger Neil Findlay lost to Jim Murphy, attracted total donations of around £65,000, two-thirds for Mr Murphy.

After a month as leader, Mr Leonard is expected to name his shadow cabinet this week amid reports Ms Dugdale will be sidelined after a formal warning for appearing on the ITV reality show I’m a Celebrity without permission from the party.