SNP leadership candidate Ash Regan has said there is “absolutely no substance” to the independence plans of her fellow contenders, comparing them with a “bag of marshmallows”.

Speaking during a hustings event in Inverness on Saturday, the candidate sought to lay out her vision for leaving the UK, which would see any majority for independence supporting parties at a Westminster or Holyrood election taken as a trigger for negotiations to start with Downing Street.

Dubbed the “voter empowerment mechanism”, Ms Regan has repeatedly said it is different from the de facto referendum plan put forward by outgoing First Minister Nicola Sturgeon.

The plan drew groans from the audience at a similar event on Friday, but less than 24 hours later, Ms Regan was on the offensive.

“We’re in a position where we’re just doing more of the same all the time,” she said.

“We’re piling up mandates and I’m afraid to say that’s what both my colleagues are suggesting right now.

“Their plan is a bit like giving you a bag of marshmallows – it looks quite nice, it sounds quite nice, but ultimately there’s absolutely no substance to it whatsoever.”

Scotland “cannot keep begging” for a referendum on independence, she added, saying Westminster will not allow Scotland to have another vote on the issue, and the SNP had to “accept” that.

Responding to Ms Regan’s comments, Health Secretary Humza Yousaf joked: “I quite like marshmallows, I won’t lie.”

Mr Yousaf’s plan would see the SNP try to build popular support in the country, as opposed to talking about process, telling members “there is no ruse” that could see Scotland win its independence, adding that “the most formidable politician on these islands, Nicola Sturgeon, would have figured it out by now”, if there were.

“I think this idea that if we get 50% plus one then we can demand negotiations and instruct the UK Government to march up the road to Edinburgh, I don’t think that works,” he said.

“I’ve been in government for over 10 years. When there’s been a crisis and we need to get the UK Government on the telephone it’s been hard enough, let alone getting them to come up the road to Edinburgh to get them to hold negotiations and discussions.”

“No option,” he said, would be taken off the table.

Meanwhile Finance Secretary Kate Forbes said competent government would help to persuade people to the independence cause, as well as “sketching out” how the first few years of an independent country would look.

Meanwhile, Ms Forbes said she wanted Highland Council to be broken up.

Concerns have long been raised about the size diversity of the council area, which covers more than 25,000 square kilometres and includes some of the country’s most remote areas as well as Inverness.

Asked what they would do to put power in the hands of local communities, Ms Forbes said: “Let’s start by breaking up Highland Council.”

Her response was met with applause and cheers from members attending the event.

“We know in the Highlands and Islands, the approach to social care, the approach to local government, the approach to filling in the potholes, is going to look different in Portree than it does in Inverness.

“We need to get back to what we were all about as a party, which was empowering those in local communities to make the best decisions for the people that they serve.

“That’s my approach to independence … it’s not rocket science, it’s that those that live in Scotland are best placed to make decisions about affairs that matter to Scotland, and I think that needs to be the approach that we take to power more generally.”

Ms Forbes did not say how many more councils the break-up would result in.

The Finance Secretary went on to say there needed to be a “serious conversation” about where power lies.

Ms Regan agreed with Ms Forbes’ position, saying the Highland Council area was “enormously large and it means people don’t feel connection in the way decisions are made”.