The SNP must use Theresa May's Brexit negotiations as a "blueprint" for how not to campaign for independence, the Justice Secretary has said.

Scottish independence campaigners should learn from the former prime minister's attempts to appeal to the "extremes" when negotiating her failed Brexit deal, Humza Yousaf told an event at the Edinburgh Festival Fringe.

He said the SNP "can't just rely on the rest of the UK being a complete basket case" but said Brexit is providing a "sea change" in strengthening support for Scottish independence.

Mr Yousaf said: "The SNP has to look at the arguments (from the 2014 referendum campaign) and where we lost those arguments.

"Person after person said to me that our economic case was just not strong enough and, not just that, they didn't quite believe what we were telling them."

Describing how he hopes the SNP can convince people to back independence, he said: "The facts, the substance, are massively important but so too is the tone and the manner in which you do it.

"If Theresa May's handling of Brexit has shown us anything - how you negotiate, how you take people forward, how you take the country forward in a united fashion - if there's a blueprint of how not to do it, then she has created it."

Commenting on the controversial Growth Commission report, he said it "paints a realistic picture", adding: "It doesn't tell you that independence is going to be a land of milk and honey because it ain't.

"We're going to have challenges like any other country has."

Mr Yousaf, who was in the Scottish Government's Brexit meeting with the UK Government about policing and justice on Friday morning, described Boris Johnson's position as "an abdication of responsibility".

He said: "It's just so disconcerting but also really unconscionable that a government can actively choose as a policy something that it knows will be so, so damaging and catastrophic to the country as a whole.

"It will be catastrophic but it's now become an active policy choice rather than just an option.

"The fact that the Government can inflict this on people is just an abdication of responsibility."

Asked whether it was "time to drop the nationalism part" of the SNP's name, Mr Yousaf said: "I do struggle with it because people associate it with all the various elements of nationalism that exist.

"I think the brand is so strongly associated that a name change would be difficult and challenging. "But I think if I was in those discussions when the SNP was made, I would have thought of perhaps looking at a different name because of the connotations of nationalism."

He added: "Now, for me, I don't think anybody that really knows the SNP, knows the people involved in the SNP, knows the core of the SNP, thinks that we are associated at all with that nasty, right-wing nationalism, at all.

"Not to say that there aren't bad apples who support us and whatever else, and we must weed them out, root them out.

"But the core of where we are is nothing to do with those nefarious elements of nationalism.

"I think people understand that we are an open and inclusive party. But do I think that the name can present us with some challenges? For sure."