HUMZA Yousaf has taken a swipe at Kate Forbes as the SNP leadership race heats up.

It comes after Forbes, the frontrunner in the race, faced criticism for saying she would have voted against equal marriage had she been in parliament at the time.

She told the Scotsman: "I believe that it should be a conscience vote because of its profound significance in all mainstream faiths.

"I think for me, Angela Merkel is the example I would follow, I would have voted, as a matter of conscience, along the lines of mainstream teaching in most major religions that marriage is between a man and a woman.

"But I would have respected and defended the democratic choice that was made."

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However, in a clear swipe at his main rival, Health Secretary Yousaf said that religion should not be the basis for legislation.

Speaking to Andrew Marr on LBC, Yousaf said: "I'm a supporter of equal marriage. Let me get to the crux of the issue that you're asking me. I'm a Muslim. I'm somebody who's proud of my faith. I'll be fasting during Ramadan in a few weeks’ time.

"But what I don't do is, I don't use my faith as a basis of legislation. What I do as a representative, as a leader, as a Member of the Scottish Parliament, is my job, to bring forward policy and pursue it in the best interest of the country.”

Forbes’s admission has been seen as a torpedo for her hopes of becoming first minister. It was reported that one senior member of her campaign team said she had “f***ed it”.

And former Scottish Tory leader Ruth Davidson said: "I'm not an in-depth student of the SNP membership, but I'm pretty sure that, with this, Kate Forbes has just set fire to her leadership campaign on the very same day as she launched it."

It comes as a poll conducted from February 15-17, in the wake of Nicola Sturgeon’s resignation, found that Forbes was leading in approval ratings. She had a 19-point lead over Yousaf.

Amid concerns about what impact a Forbes win could have on the governance deal with the Greens, Yousaf made clear he backed the agreement remaining in place.

“I'm a wholehearted supporter of that deal, because it's brought stability to the government," he said.

“But frankly speaking, it would do enormous damage to the independence movement, if we had two parties that were working well together, split up, have that divorce, frankly, and that's not going to go down well for anybody.

“I think the Green deal has been great for not just for the government, but actually we've brought forward some really radical reforms. So, I'm a great supporter of it.”