The shop workers union Usdaw has chosen to back Richard Leonard in the Scottish Labour leadership contest, it has been reported.

Leonard, thought to be the preferred candidate of Jeremy Corbyn’s office, has secured the support of Usdaw as his rival Anas Sarwar has become embroiled in a row over wages.

Reports in Huffington Post confirm that the union has backed Leonard. A spokesperson for Usdaw said to the online publication: “I can confirm that Usdaw has nominated Richard Leonard for Leader of the Scottish Labour Party.”

Sarwar has said that his family’s firm does not pay the voluntary living wage, though he has said that he supports the higher pay rate becoming mandatory. He is not a director of the firm.

In a BBC interview the Glasgow MSP Sarwar said: “The difference is that I don’t support a voluntary real living wage.”

“I support a mandatory real living wage. I don’t think it is right that the market dictates what a fair day’s pay is. That is why I want it to be a compulsory policy.”

Usdaw joins the more left leaning unions of TSSA, Aslef and Unite in backing the Yorkshireman and Central Scotland MSP Leonard in the race to replace Kezia Dugdale in Scottish Labour’s top job.

The new leader will be announced on November 18th. You can see the full timetable for the contest here.