Kate Forbes has said her campaign to replace Nicola Sturgeon as First Minister is “absolutely not over”, as a backlash over her equal marriage views has seen her support ebb away among MSPs.

The Finance Secretary said on Monday that her conscience would not have allowed her to vote in favour of same-sex marriage, which passed in Holyrood in 2014, if she had been an MSP at the time.

In the hours after her speech, a number of early supporters of her campaign among the party’s MSP group withdrew their backing.

These included: Public Finance Minister Tom Arthur; Minister for Children Clare Haughey; and Health Committee convener Gillian Martin.

Ms Forbes, Health Secretary Humza Yousaf and former community safety minister Ash Regan are running to replace Nicola Sturgeon as SNP leader and First Minister following her surprise resignation announcement last week.

The Finance Secretary, a member of the Free Church of Scotland, was asked on BBC Radio’s Good Morning Scotland programme if her campaign was over before it began.

She replied: “Absolutely not. We have a large party membership, most of whom are not on Twitter.

“I understand people have very strong views on these matters. I think the public are longing for politicians to answer straight questions with straight answers and that’s certainly what I’ve tried to do in the media yesterday. That doesn’t necessarily allow for much nuance.

“My position on these matters is that I will defend to the hilt everybody’s rights in a pluralistic and tolerant society, to live and to love free of harassment and fear.”

Ms Forbes later said she regrets the pain caused by her comments. On Times Radio, she said: “I regret enormously the pain or hurt that has been caused because that was neither my intention, and I would seek forgiveness if that is how it’s come across.”

Ms Forbes added that she defends the rights of LGBT+ people to live “free of harassment, fear and prejudice”.

Meanwhile, Mr Yousaf has said he will “always fight for the equal rights of others”.

Asked what he thought of what Ms Forbes had to say on same-sex marriage, he told the Good Morning Scotland programme: “It’s for her to defend her views, I’ve made my views very clear.

“I think my track record on equality issues speaks loud and clear.

“I’m a minority in this country, I have been my entire life and my rights don’t exist in some kind of vacuum, my rights are interdependent on other people’s rights and therefore I believe very firmly, in fact with every fibre in my being, that your equality is my equality, therefore I’ll always fight for the equal rights of others regardless of who they are.”

It comes after Mr Yousaf said in an interview with Andrew Marr on LBC on Monday that he would not legislate on the basis of his faith and is a supporter of equal marriage.

On Tuesday morning, Mr Arthur said he was no longer able to support Ms Forbes’ campaign.

The minister tweeted: “Equal marriage is amongst our Parliament’s greatest achievements and one that I would have been proud to vote for had I been an MSP when it was passed.

“Consequently, I am unable to continue to support Kate’s campaign.”

Aberdeenshire East MSP Gillian Martin said she had wrestled with the issue overnight.

On Tuesday morning, she tweeted: “We must be full throated in our support of equal marriage. No if or buts. I won’t be supporting Kate’s campaign on that basis.

“I wish her well- she’s extremely talented. But I have red lines. And this is one.”

Fulsome support for equal marriage or nothing

Speaking to journalists in Holyrood later on Tuesday, Ms Martin said: “I felt that I couldn’t support Kate any more, because for me that’s a red line

“Fulsome support for equal marriage or nothing.”

She said she had not yet considered giving her backing to anyone else at this point.

Ms Forbes has also said she would not have voted for the Scottish Government’s controversial Gender Recognition Reform (Scotland) Bill in its current form.

As she was on maternity leave, she did not participate in the final vote before the new year but has been clear on her opposition since 2019.

Ms Regan is also opposed to the Scottish Government’s gender recognition reforms, stepping down from her role as community safety minister to enable her to vote against the legislation last year.

Mr Yousaf has previously promised to stand by the Gender Recognition Reform (Scotland) Bill and challenge the Section 35 order from the UK Government which seeks to block the legislation.

Speaking on the BBC, he described it as “an attempt by the UK government to undermine the democratic will of the Scottish parliament” and suggested Westminster was trying to “stoke a culture war.”

He told interviewer Laura Maxwell: “It is the principle here that no UK government minister should be allowed to veto a piece of legislation passed by the majority of the Scottish parliament.

“So I respect the point that your were making, there are clearly people in society that disagree with the GRR bill, I’m not disagreeing with you on that point.

“My point is, whether you agree or disagree, the fundamental principle here is a piece of legislation passed by the majority of parliament which has a red pen put through it by the UK government on a whim and that is not acceptable regardless of whether you believe in the legislation and the substance of it or not.”