Humza Yousaf, who is the early favourite for the top job, said he had “concerns” about fighting the next general election as a de-facto referendum, as Ms Sturgeon has advocated.

However, he stood behind the outgoing First Minister’s controversial gender reforms, insisting he would “absolutely” challenge the UK Government’s decision to block the legislation.

The reforms are a central dividing issue in the SNP leadership race. Kate Forbes, the finance secretary, said she had “significant concerns” about self-identification as she launched her own leadership bid, and confirmed she would not have supported the Gender Recognition Reform Bill in its existing form.

Health Secretary Humza Yousaf. Picture: Andrew Milligan/PA Wire

She was on maternity leave when MSPs voted on the issue before Christmas. Meanwhile, former minister Ash Regan, the third leadership candidate, also opposes the Bill, but is seen as an outsider in the race.

Mr Yousaf, who has been the health secretary since 2021, has already received the backing of figures loyal to Ms Sturgeon. However, at an event to launch his campaign at Clydebank Town Hall, he pushed back at suggestions he is simply the “continuity candidate”, insisting: “I’m my own man.”

He told supporters: “For too long our opponents have been desperate to talk endlessly about process, while at the same time actively refusing to grant a section 30 order despite the SNP winning regular mandates for independence.

“We need to stop falling into our opponents’ traps. They want to define independence as a question about process – we need to start talking about policy. We need to get back to the basics and remind people why they need independence.

“It’s not good enough to have polls that put support for independence at 50 per cent, 51 per cent. In order to gain our independence, we have to grow our grassroots support, so we can definitively say that independence has become the settled will of the Scottish people. We do that not by engaging endlessly in process, we do that through engaging policy and not getting stuck in that quagmire of process.”

Mr Yousaf said he believed in independence “with every fibre” of his being, and argued “political obstacles will disappear” if it becomes the settled will of the Scottish people.

He pointed to his experience in government – having held both the health and transport briefs – and argued he had the “necessary skills” to bridge political divides.

Michael Matheson, the transport secretary, was among those attending Mr Yousaf’s launch event. Kevin Stewart, the SNP social care minister, has also backed his campaign.

Ms Sturgeon had wanted to fight the next general election as a de-facto referendum, and had called a special party conference to debate the plan next month. However, this was postponed after her shock resignation announcement on Wednesday last week.

Taking questions from journalists, Mr Yousaf said: “I have some concerns about using a Westminster general election as a de-facto referendum. I’m not as wedded to it as the First Minister.”

Asked when he thought he could deliver independence, he said: "I'm not going to put a timetable on it. I want independence tomorrow if we can have it, and that goes almost without saying."

Elsewhere, Mr Yousaf said he would consider campaigning with former first minister Alex Salmond and his pro-independence Alba Party.

He said: "One of my big strengths is reaching across the political divide. I've not spoken to Alex Salmond since he started Alba. Look, I'll consider that, perhaps, at the time, but at the moment I'm focused on working with our party membership, working with the Greens, working with others who support independence to drive up the cause."

Mr Yousaf said he would want Ms Forbes in his Cabinet if he was elected first minister, calling her “an exceptional talent”. But asked about Ms Regan, he was notably less enthusiastic, saying: “Let’s see where we get to in this race.”

He said Ms Forbes was a “good fr

SNP leadership race: Humza Yousaf distances himself from Nicola Sturgeon's independence strategy