The SNP's longest serving MP has called the party's current indyref2 policy a "total mess" which "doesn't work".

Pete Wishart, who has been a Member of Parliament since 2001, also spoke candidly about Humza Yousaf, Kate Forbes, Michael Matheson and the resurgence of Scottish Labour in an exclusive interview with Neil Mackay in The Herald.

Read more:  ‘Indyref2 policy is a total mess': Wishart candidly reveals all on SNP

The MP for Perth and North Perthshire said: "We’ve decided on a policy at conference which I just don’t understand.

"It’s a total mess, it’s two contradictory things: if we get a majority of seats, we start independence negotiations, and almost concurrent we ask for more powers. It just doesn’t work.”

Instead, Mr Wishart supports the "de facto" referendum route, which former First Minister Nicola Sturgeon had put forward. 

The 61-year-old said: “I can’t see a cleaner, more elegant way, having had a clear ‘no’ from unionist parties. There’s nothing left other than this."

Read more: Matheson embroiled in 'bullying' row and urged to resign

The MP also spoke about the controversy over Health Secretary Michael Matheson's £11,000 data roaming bill for his work iPad. 

He said: “When it first emerged, just pay it, get it out of the way, don’t let it grow legs. We didn’t deal with it, we let it go on and on.

"I’m not necessarily saying Michael should have been sacked but this could have been managed a lot better. The way we allowed this to drag out, it became more about honesty and integrity than iPads. We got to that place without an effective strategy.”

Mr Wishart said he had been surprised by the success of Kate Forbes in the SNP leadership election, given the former Finance Secretary's conservative views. 

Read more: Kate Forbes: SNP should not prolong gender legal battle

He said: "At the beginning of the contest I was prepared to give Kate the benefit of the doubt. I thought … she’d be able to make a distinction between her own faith and a general view more in line with party values.

“That wasn’t possible and some of the extraordinary things that she came away with - around children out of marriage - was beyond the usual brand of social conservatism we see in some of the darker recesses of our movement. That was quite a shock.”

Meanwhile, he remarked that he wouldn't have gone near leadership candidate Ash Regan "with a barge pole".

Read the full exclusive interview in The Herald on Sunday or on The Herald website.