Former MP Tom Harris: Scottish Labour is at the edge of irrelevance

Mr Harris, a transport minister under Tony Blair and Gordon Brown, was one of 40 sitting unionist MPs unseated by the SNP's 2015 tsunami.

 The former journalist - who once stood for the leadership of his party in Scotland - said “things have never been this bad for Labour”.

He said: "I think we have come to the edge of being an irrelevant party in Scotland and there’s no God given right for the Labour Party to exist at all. I supported Kezia and I still support Kezia, I think she’s great, but I think she’s in an impossible job.”

"There may well be a way back for Scottish Labour, I don’t see how that is. The demographics are appalling for Labour at the moment.

"I think one of the reasons Kezia is finding it difficult is because of the UK leadership.

"Mostly it’s things completely outside the Labour party’s control. The key is to get someone who the Scottish people see as a potential prime minister."

Mr Harris - who ruled out a comeback - was speaking to The Herald as part of a survey of beaten MPs. Only four have chosen to run again. Many have retired or are looking for work.

Explaining his decision to register his new lobbying company, Third Avenue Communications, the former politician said: "I had been thinking about what I was going to do before the election, assuming I was going to lose. I’d spoken to a few people down in London who were in public affairs, so lobbying essentially, and having been lobbied in the last 14 years I had a good idea of what it involved."

The 51-year-old former minister is building on his experience by focusing on the transport industry.

"I think I’ve got a fairly unique experience, not only have I been a member of a select committee but I’ve been a minister giving evidence to a committee. So I’ve seen both sides of the horseshoe, and it’s something it turns out companies are quite keen to use,” he said.

Like many defeated Labour MPs, Mr Harris is glad to have lost to the SNP's Stewart McDonald, with whom he developed a very civil rivalry during the election.

He explained: "I’m enjoying being in Glasgow more and not travelling down to London every week. I like picking the boys up from school and the family like having me around. My wife Carolyn says I look younger and more relaxed than in the whole time I was an MP.

"I wish five years ago I was doing what I’m doing now. And I’m genuinely glad I lost this time because I think another five years of opposition would just be intolerable."

Mr Harris is just the latest ex Labour politician to forecast the party's extinction.

His remarks came after fellow former MP Ian Davidson suggested the party had been in denial over the scale of the SNP surge.