SCOTTISH Labour’s leadership battle has descended into chaos after a hustings in Dunfermline saw the two men vying for the top job accuse each other of lying about Brexit and Jeremy Corbyn.

In the debate, which was filmed by ITV Borders, the acrimony started when Sarwar said Leonard’s decision to rebel against the Scottish party line during a vote over Europe earlier this year, means he cannot command the loyalty of MSPs.

Sarwar said: “Richard was one of them who broke the Labour whip to vote with the Tories to trigger Article 50. I think that was a mistake.

“The Labour leader will always ask for loyalty from his MSPs and his party, and I think you can only credibly ask for that loyalty if you’ve shown loyalty yourself.”

Leonard replied, suggesting Sarwar was not in a position to question anyone else’s loyalty: “You raise the word loyalty Anas, and I’m bound to say you signed a letter calling for Jeremy Corbyn’s resignation when 60 per cent of the Labour Party voted for him.

“And as for the symbolic vote which the Scottish Parliament held in February, in discussions we had a week before Anas was on the same side of the argument as me, and then he changed his position over the course of the next week. So you can draw your own conclusions from that.”

Sarwar, shaking his head as Leonard speaks, then replied: “I would caution Richard to be very, very careful about talking about private discussions, because I know what private discussions he was having with me about Jeremy Corbyn.”

Commenting, SNP MSP Joan McAlpine said:“The Labour leadership campaign just gets dirtier and dirtier. If this is what they’ll say in front of TV cameras, what are they saying privately?

“It’s easy to forget that this pair are supposed to be on the same side – but as usual Labour are more interested in their internal spats than on taking on the Tories. It’s a dereliction of duty. Labour’s continued infighting on Europe is putting Scottish jobs and our economy at risk. This isn’t the time for navel gazing. We need a united front standing up for Scotland’s place in the single market and customs union.

“Clearly whoever wins this contest, they’ll be serving their own clique rather than the people of Scotland.”

Earlier this week Kezia Dugdale was withering about the two men fighting for her old job. In her column for the Daily Record, the former Scottish Labour leader said there had been an “absence of any new ideas in this leadership contest.”

“Richard Leonard tells us that health inequality is the big challenge facing the country, yet his plans to address this include a new ministerial post and an audit to make sure the cash gets spent in the right places. More managerial than radical,” she wrote. “Anas Sarwar tell us his mission is to save the NHS. It’ll take more money and more staff in his view. But he’s yet to say anything about how to keep people out of hospital altogether.”

She added: “One of the few advantages of a contest like this, is that it offers a real chance to reset the policy direction of the party but so far we’ve just had the same old tune from both camps, just mixed at different tempos and levels of base. If either camp want my vote, they’ll need to say something fresh, new and relevant to the challenges ahead.”

The party has come close to civil war during this contest.

Last week, Scottish Labour’s bungling caretaker leader Alex Rowley was recorded speaking candidly about Dugdale to an American student while standing in queue for an event at conference in Brighton.

The gaffe-prone Fifer told his new acquaintance that the left of the party were caught off-guard by Dugdale’s surprise resignation, and he seemed to hint at a possible coup: “We didn’t expect this to happen, and we certainly weren’t putting any pressure on it.”

But, he later adds, they did think it “would happen before 2021” and there had been “private discussions” about how it should happen.

Jackie Baillie, a prominent Sarwar supporter said Leonard needed to clarify if he had played any role in the plot. Leonard’s team called the allegation the “latest Jackie Baillie pish”.