There is “no magic wand” that can deliver independence, the favourite to become Scotland’s next first minister has warned his governing Scottish National party, saying a sustained majority for leaving the UK was vital to overcome Westminster’s veto of a second referendum on the issue.

The comments from Humza Yousaf, Scotland’s health secretary and the bookmakers’ frontrunner to replace Nicola Sturgeon as first minister, are likely to dismay those SNP members who are impatient with the party’s failure to make progress on ending Scotland’s 316-year union with England.

In an interview with the Financial Times, Yousaf, 37, said he wanted an end to the “rotten union” as urgently as anyone, but also made clear he did not support Sturgeon’s plan to use the next Westminster general election as a “de facto” referendum on leaving the UK.

The UK government has refused to allow a second referendum on independence after Scots in 2014 backed remaining in the union by 55-45 per cent, and the supreme court ruled late last year Scotland could not unilaterally hold such a vote. Polling shows that the Scottish electorate is split roughly down the middle on whether or not to leave the UK.

“There’s not a ruse, there’s not something that we can simply cook up, there’s no magic wand that can deliver independence because the UK government has denied the preferred route,” Yousaf said.

“The route to independence is by growing popular support. If independence becomes the sustained will of the Scottish people, then those political obstacles that are put up by Westminster governments [will be] overcome,” he added.

Speaking after a leadership campaign event in the central Scottish town of Lanark, Yousaf said that if he won the leadership election, which ends on March 27, he would “in the first week” establish regional assemblies of SNP members to allow them to consider “every option that’s within the legal framework” for achieving independence.

A loyal lieutenant of Sturgeon who was given the job of guiding the Scottish health system’s recovery from Covid-19, he is pitching himself as a defender of the first minister’s record while also signalling potentially important changes of approach.

Sturgeon repeatedly assured SNP members that a second independence referendum was close, but her eventual resort to the “de facto” vote divided her party and weakened her authority.

Yousaf’s rivals for the leadership, finance secretary Kate Forbes and former SNP community safety minister Ash Regan, have also disavowed the de facto referendum plan, but have signalled they could seek a more rapid progress on independence. Forbes said this month she would “fight for the right” to hold a referendum within three months of the next UK general election, which is expected next year.

“Anybody who is selling a route to independence which suggests that it can be done in a matter of weeks or months, I’m afraid, is being disingenuous,” said Yousaf, who was the first member of an ethnic minority and first Muslim to be appointed to Scotland’s cabinet.

Unlike his rivals, the health secretary is a strong defender of legislation championed by Sturgeon to make it easier for trans people to get official recognition of a change of gender.

Regan resigned from the government last year over her opposition to the bill. Forbes, who was on maternity leave at the time, has said she would not have voted for it.

Yousaf has vowed to challenge the UK government’s decision to use constitutional powers for the first time to block the gender reform legislation, which was supported by two-thirds of MSPs.

Yousaf said it did not matter whether one agreed with the gender reform.

“The substance of the issue is whether we allow the UK government to override legislation that was passed by a majority of our parliament. I’m pretty disappointed that I’m the only candidate who is committed to that unequivocally.”

The health secretary also sought to paint himself as the best defender of Sturgeon’s redistributive policies. Her government has used devolved powers to impose slightly higher rates of income tax on wealthier residents than elsewhere in the UK, while introducing benefits that include a £25-a- week child payment for poorer families.

“I’m unashamedly and unapologetically progressive in my views on the distribution of wealth,” Yousaf said, though he suggested he had no intention of further widening the divergence with London.

“At the moment, we’ve got the right balance between progressive taxation and the work we are doing to ensure we get people into work and grow that revenue base.”

A Savanta survey of 515 members of the SNP for The Telegraph this week found 31 per cent supported Yousaf, ahead of Forbes and Regan, but 32 per cent said they did not know whom they might back.

Sturgeon has not endorsed a candidate in the leadership race, but Yousaf is widely seen as the preferred choice of the first minister and most party heavyweights. A string of SNP parliamentarians have already backed his campaign.

But while Yousaf praised Sturgeon’s record, the health secretary appeared to share the dissatisfaction of other colleagues at what they see as her top-down approach to party management and reliance on a small group of confidants that includes her husband, Peter Murrell, SNP chief executive since 1999.

Yousaf said he had a “different leadership approach” from Sturgeon who worked though an “inner circle”.

“I certainly want to see reform of the headquarters and I would have an early discussion with the chief executive to understand what his plans are.”

Opposition politicians have accused Yousaf of failing to prevent a crisis in healthcare over the winter and to reform an increasingly strained NHS. But he said serving as health secretary and previous stints in transport and justice made him “by far the most experienced candidate in the toughest jobs in government”.

“It’s the jobs like health secretary that build up your resilience.”