Scottish independence represents the opposite of the “narrow isolationism” of Brexit, the SNP’s depute leader is to say.

Keith Brown, MSP for Clackmannanshire and Dunblane, will speak to supporters of independence at a one-day conference in Aberdeen on Sunday.

He will make the case for Scotland leaving the UK in a future referendum.

Mr Brown is expected to say: “Many of us who support independence have long viewed Westminster as a failing institution.

“But even we would have struggled to predict the complete meltdown caused by Brexit.

“Brexit Britain offers narrow isolationism – while independence offers the opposite.

“Independence is about Scotland joining Europe and the rest of the world as an equal partner – not about throwing up new barriers like Brexit does.”

The SNP depute leader is also expected to tell supporters they should make the case to people who voted against independence in 2014 with “patience, empathy and kindness”.

He will say: “People across Scotland are looking at this chaos unfolding and they’re wondering how it’s even possible.

“Many who voted No in 2014 are horrified – even if they might not yet be prepared to back independence. It’s our job to persuade them with patience, empathy and kindness.

“Brexit is a symptom of Westminster’s failings as much as the cause. A Tory Government, without a mandate in Scotland, delivering Brexit, which was rejected in Scotland. Independence will mean that decisions about Scotland will be made by the people of Scotland.

“People are ready to listen to that case. We need to show why it’s an opportunity worth taking.”

But a spokesman for Scottish Labour suggested another referendum on independence would lead to “more division and instability”.

He said: “The fact the SNP is bending over backwards to claim a second referendum on independence wouldn’t lead to ‘chaos’ says a great deal.

“The SNP is only interested in fostering more division and instability, but that’s the last thing we need.

“People will be right to ask why Keith Brown isn’t talking about the brutal cuts in his council of Clackmannanshire.”

Pamela Nash, chief executive of Scotland in Union, accused Mr Brown of having a “narrow-minded vision”.

She said: “This a laughable claim from the SNP. Breaking up the world’s most successful union after more than 300 years would be massively more complicated and painful than leaving the EU.

“Independence would be eight times as costly as even the worst-case Brexit, leading to devastating spending cuts and tax rises. That’s why many former Yes voters now want to remain in the UK.

“Keith Brown’s narrow-minded vision might appeal to supporters at this conference, but the majority of Scots know we are better off together and want the SNP to drop the threat of a divisive and unnecessary second independence referendum.”

Scottish Conservative MP David Duguid said: “This is embarrassing stuff from Mr Brown.

“He attacks Brexit and claims independence will mean decisions about Scotland are taken by people living here. Yet, under the SNP’s plans, Scotland would go straight back into the hated Common Fisheries Policy – handing back control over our waters to the EU.

“Far from regaining decision-making powers, we would be surrendering them all over again.

“This boomerang attack only goes to show just how utterly out of touch the SNP has become with the North East and our vital offshore fishing industry.

“He must do better. Mr Brown needs to go home and think again.”