A press officer for left-wing Scottish Labour leadership candidate Richard Leonard who used offensive language in a press release earlier this week has left his communications role.

Stephen Low, who described a Labour MSP’s comments as “pish”, is no longer part of the team.

A Leonard campaign spokesperson said: “Stephen was volunteering on media for the campaign and is no longer doing so.”

A senior Scottish Labour source said: “Richard’s decision to bring Stephen Low on board raises a lot of questions about his judgement.”

It has also emerged that Low was volunteering on the campaign while being on sick leave from his day job at trade union Unison.

He said the arrangement was to help him prepare for a return to work and had been agreed with the union.

Leonard is up against centrist MSP Anas Sarwar for the vacant party leadership and the contest has so far been marked by a series of rows over the employment practices of the Sarwar cash and carry firm.

However, Leonard also been feeling the heat over claims interim leader Alex Rowley is backing him in the contest.

Rowley has said in public that he is neutral, but a secret recording made clear he strongly favours Leonard over Sarwar.

The recording also led to claims that Rowley was involved in a plot to hasten the departure of Kezia Dugdale as leader.

Jackie Baillie MSP, a Sarwar supporter, said there was "evidence of a plot going on behind the scenes for months" against Ms Dugdale's leadership, calling this "a complete betrayal of the membership and every value we hold dear".

Responding to the claims, Low sent an email on behalf of the Leonard campaign which referred to the “latest Jackie Baillie pish.”

Low, a member of Scottish Labour’s governing Executive, will not be part of the Leonard communications team from today onwards.

Asked earlier in the week whether he is off on sick leave from his employer, Low texted:

“I'm signed off work until the middle of October - I suggested to my employer that helping out with richard's campaign could help me prepare for a return to work. They agreed.”

Low, who was a BBC journalist before joining Unison, is known for his robust views on social media platforms.

In June, referring to the Daily Mail, he wrote: “It's almost like its [sic] a contemptible reactionary shitrag.”