THE three MSPs vying to become the next SNP leader and First Minister are preparing for a second TV debate.

Kate Forbes, Ash Regan and Humza Yousaf will take part in the televised hustings on Channel Four on Thursday.

The contenders faced off on Tuesday and attacked each other in a frank and at times angry debate.

READ MORE: SNP candidates fall out in first TV debate for party leadership

Opponents said the three, who either are or have been in Nicola Sturgeon’s Scottish Government, were attacking their own party.

Two of the contenders, Forbes and Yousaf, today defended their conduct in the campaign.

Yousaf said: "I've been very clear from day one that my campaign will be a positive one, that's what people want to see from their First Minister, it's what they want to see from their party leader.

"If anybody goes low, I'll keep going high and I've said that to every single person connected to my campaign - I've got a positive vision of how we can create and continue to create a socially just Scotland.

"I'll not be slinging any mud at anybody, if people want to do that towards me that's their prerogative.

"I'll keep positive and everybody connected to my campaign will remain positive.”

While Forbes said: "I think the public and SNP members want to see somebody who's got the guts to recognise what needs to change and also recognises that we need to have a plan to deliver.

"Last night was all about having the candour and the honesty to say more of the same is not what Scotland needs.

"If any SNP leader and first minister is going to be taking on the Tories in Westminster, for example, they need to have the mettle and the courage to do that.

"That was what was on display last night."

READ MORE: MSP tells of being 'scared' after using late night bus in Glasgow

During the hour-long debate Forbes had attacked Yousaf’s record.

She said: "You were a transport minister and the trains were never on time, when you were justice secretary the police were stretched to breaking point, and now as health minister we've got record-high waiting times.

"What makes you think you can do a better job as First Minister?"

While Yousaf retorted that Forbes lost MSPs from her campaign team and alienated Yes voters, he questioned her commitment to equality following her remarks on equal marriage and said a government led by her would be “lurching to the right”.

Opposition parties said the debate showed the SNP was not up to governing Scotland.

Jackie Baillie, Scottish Labour deputy leader, said: “After 15 years of SNP failure, Scotland is crying out for change.

“But all the SNP can offer Scotland is the politically illiterate Ash Regan, the social and economic conservative Kate Forbes and the dangerously incompetent Humza Yousaf.

“Frankly, I would not trust these candidates to run a bath let alone a country.”

Craig Hoy, Scottish Conservative chair, said the SNP was now “openly at war with itself”.

He said: “The candidates spent the debate torching each other and their party’s record in government.”