Labour sources say Mr Sarwar rejected the party’s seating plan for First Minister’s Questions which had been stage-managed in an effort to present a united front for the television cameras.

Labour MP Hugh Gaffney to attend '˜diversity training' after Burns Night rant

The intention had been for Mr Sarwar to sit next to Scottish Labour leader Richard Leonard for the set-piece event. A What’sApp message was sent announcing the seating plan at a time when Labour has been under scrutiny over how it has dealt with offensive remarks Mr Gaffney made about the Chinese and LGBT communities.

Anas Sarwar refused to sit next to Scottish Labour leader Richard Leonard (pictured). Picture: Jeff J Mitchell/Getty Images

But when Mr Leonard stood up at First Minister’s Questions Mr Sarwar was not beside him on the front bench. Labour sources yesterday claimed Mr Sarwar, who was defeated by Mr Leonard for the Scottish Labour leadership, took the view that the plan was “tokenistic”.

In recent weeks Mr Sarwar has spoken strongly against racism, claiming a Labour councillor told him that Scotland “wasn’t ready for a brown, Muslim, Paki”. Davie McLachlan, the party’s group leader on South Lanarkshire Council, is being investigated over the incident.

Cllr McLachlan denies making the remarks.

After First Minister’s Questions, Mr Leonard defended his decision not to suspend Mr Gaffney, who used the word “bent” and used an unacceptable term for a Chinese meal while delivering the Immortal Memory at a Labour students Burns Supper in Edinburgh.

Mr Leonard told journalists: “Hugh Gaffney’s been reprimanded. He’s made a full apology. I have spoken to the Chinese for Labour Group and he’s referred himself to equality and diversity training.”

When asked why Mr Gaffney had not been suspended, Mr Leonard said the politician was not disputing the allegations made against him.

“He’s admitted it and under those circumstances the appropriate action has already been taken.”

Mr Leonard rejected the suggestion that his colleagues at Westminster had put him under pressure not to suspend Mr Gaffney.

When asked about the nature of Mr Gaffney’s reprimand, Mr Leonard said he had not yet spoken to the MP for Coatbridge, Chryston and Bellshill but intended to do so later that day.

“He’s been spoken to at Westminster and I’ll be speaking to Hugh Gaffney this afternoon,” Mr Leonard said.

Mr Sarwar said he expected Labour to take action against racism. He said: “Equality and diversity training is not a punishment. Equality and diversity training should be compulsory for every elected member, for anyone who seeks office and indeed for everyone across the country whatever workplace they are in. What I would urge the Labour Party to do, is not to give us words.

“Solidarity is welcome but solidarity is not enough. I expect deeds.”

Racism row deepens as Anas Sarwar snubs Richard Leonard