THE Scottish Labour leadership race has turned personal, with Anas Sarwar and Richard Leonard revealing the content of private conversations to attack each other.

At a party hustings in Dumfries, left-winger Mr Leonard said his centrist opponent had flipped his position ahead of a Holyrood vote on Brexit.

Mr Sarwar then threatened to reveal Mr Leonard’s private thoughts on Jeremy Corbyn.

The SNP said the contest was getting "dirtier and dirtier".

The Monday night clash was captured on camera by ITV Border.

It followed a question about Brexit and a discussion of a symbolic Holyrood vote in February when most MSPs voted against the UK government triggering Article 50.

As Jeremy Corbyn’s position was not to stand in the way of Brexit, the vote pitted then Scottish labour leader Kezia Dugdale and most of her MSPs against him.

However three Labour MSPs who supported the UK leader - Mr Leonard, Neil Findlay and Elaine Smith - voted alongside the Tories in favour of triggering Article 50.

Mr 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.”

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

That prompted Mr Leonard to remind the audience Mr Sarwar last year signed an open letter calling on Mr Corbyn to quit, though he now says he wants him to be Prime Minister.

Mr Leonard said: “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 that 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.

“You can draw your own conclusions from that.”

Mr Sarwar is seen shaking his head in disgust at Mr Leonard’s remarks.

The Glasgow MSP then warned: “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 before that vote.”

A source who was present when MSPs were discussing how to vote on Article 50 said: “Those who aspire to lead the party should keep MSP group discussions private, and Richard is misrepresenting the situation here – a lot of MSPs were initially concerned the SNP would seek to make the Holyrood vote on Article 50 about a second independence referendum and an independent Scotland joining the EU.

“After cross-party talks there was absolutely no mention of independence in the motion that parliament voted on, but Richard still decided to be disloyal to Kez, break the whip and join with the Tories.”

The exchange echoes one of the most controversial moments in the run up to the June General Election, when Nicola Sturgeon disclosed the content of a private conversation with Ms Dugdale during a live TV hustings.

The First Minister claimed Ms Dugdale told her immediately after the EU referendum vote, that Labour might drop its opposition to a second independence referendum - a claim Ms Dugdale said was a lie.

Ms Dugdale’s chief spin doctor, Alan Roden, who now works for Mr Sarwar, called Mr Sturgeon’s comments “insulting and demeaning” to her office and an “act of desperation”.

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 these 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.

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