Humza Yousaf has told his party to stop talking about the “process” of independence, as debates over de facto referendums and mandates “just don’t interest people”.

In a striking admission of failure, he said that, despite his party being in power for 16 years, voters “don’t understand why independence is relevant to their everyday lives”.

He said he wanted a debate on independence strategy at this weekend’s SNP conference in Aberdeen to “draw a line under it” and let the party focus on policy instead.

After that debate, “we’re done”, the First Minister said in a blunt message designed to make his party appear more outward-looking and less preoccupied with talking to itself.

It marks a break with Nicola Sturgeon’s period as First Minister, which saw repeated draft referendum Bills, roadmaps and other supposed staging posts to independence.

Delegates are due to vote tomorrow on what approach the party should take to the general election and how to interpret the result.

Mr Yousaf and SNP Westminster leader Stephen Flynn proposed last month that the SNP winning “most” of Scotland’s 57 redrawn seats next year would be a mandate for independence talks.

However, members are expected to raise the bar to a “majority” of seats, a position Mr Yousaf originally proposed at a convention in June before he and Mr Flynn diluted it. 

If delegates revive the “majority” plan, the party would regard winning 29 MPs as the trigger for negotiating the end of the Union or securing a new independence referendum.

However both Labour and the Tories have already ruled out accepting the SNP’s interpretation of the result, potentially rendering the whole exercise academic.

The SNP’s independence strategy has been in turmoil since Ms Sturgeon secured a ruling from the UK Supreme Court on whether Holyrood could hold Indyref2 unilaterally.

Five justices unanimously said that it could not, a decision that confirmed Westminster’s agreement was needed for a new vote and left the SNP at a loss. 

Mr Yousaf said he was open to amendments to the plan he and Mr Flynn proposed, such as winning a majority of MPs, but urged the party to put an end to the argument after Sunday.

Speaking to the PA news agency, the SNP leader said: “Let me be very frank about this.

“At conference, once we’ve had that debate - and I’m sure in the best traditions of the SNP, it’ll be frank, it’ll be robust - that’s it. We’re done. You draw a line under that. 

“I will fully accept whatever conference decides. Everybody else must accept what conference decides. Once that is done, the talk about process is done.”

Mr Yousaf, who narrowly defeated Kate Forbes to become SNP leader in March, said support for his party had dropped recently as it kept discussing how to achieve independence rather than the reasons for it, even as support for independence remained around 50%.

He said: “One of the things that is very clear to me, why that link between independence supporters and the SNP is weakened, is because we are talking too much about process.

“People don’t understand why independence is relevant to their everyday lives; the cost-of-living crisis, the NHS and public services and the economy.

“We have to draw a line under it on Sunday. 

“The party’s had the debate, it’s had its regional assemblies, it’s made a decision – let’s all get united behind it and let’s get on with talking about the policy, not the process.”

He also told the Guardian newspaper: “De facto referendums and general election majority votes … just don’t interest people. And we have to now begin talking about how independence is relevant to the cost of living crisis.”

The SNP’s three-day gathering in Aberdeen opens tomorrow against the most troubled backdrop the party has experienced since it came to power in 2007.

After Ms Sturgeon quit in the spring, a bruising leadership contest was followed by auditor problems, arrests in the police probe into party finances, Labour winning the Rutherglen & Hamilton West by-election, internal feuding and MP Lisa Cameron defecting to the Tories.

There have also been divisions in the SNP over governing with the Scottish Greens, policy reversals and rebellions, and the suspension of former cabinet secretary Fergus Ewing.

Asked if he was setting himself up for more divisions after tomorrow’s debate, the FM said: “I genuinely hope not. People can accuse me of a lot of things, but I can’t be accused of not letting the party have its say on the strategy.”

He said he was both “excited” and “nervous” about his first conference as SNP leader, likening it to a “very big family gathering”, adding: “Every family has its awkward members.”

Deputy First Minister and Finance Secretary Shona Robison has warned the Scottish Government faces a £1 billion black hole in its budget next year.

However Mr Yousaf said that, despite the financial restraints, his closing speech on Tuesday would not be “just rhetoric” but would include some “solid policy detail and vision”.

Tory MSP Donald Cameron said: “Humza Yousaf should be drawing a line on his plans to treat the next General Election as a proxy referendum. It is clear the SNP leader wants to waste more taxpayers’ money on his independence obsession and will ignore the real issues facing Scotland such as the cost-of-living crisis and tackling NHS waiting times.”

Pamela Nash, head of Scotland in Union and a Labour election candidate, said: “It’s not just time for the SNP to stop talking about process, it’s time for the SNP to stop talking about breaking up Britain altogether.”