Image copyright Getty Images Image caption Did the Monty Python team foresee the Labour leadership contest?

The Labour leadership contest is already being compared to Monty Python's Four Yorkshiremen sketch, as the contenders compete with each other over who has the most humble background.

No-one has claimed their family lived in a brown paper bag in a septic tank, like one of the characters in the sketch, but it is surely only a matter of time.

Surprisingly few Labour leaders have come from genuinely working-class backgrounds - and there is little evidence that voters care about whether they did or not.

So what's behind the "prolier-than-thou" sparring?

Rebecca Long Bailey clearly feels her staunch working-class roots in Salford are a major asset in the battle to be the next Labour leader.

"I'm not a millionaire or a landlord, and I didn't go to a posh school," she wrote, in the Tribune article announcing her candidacy.

This was a not-so-subtle swipe at her rivals. The "millionaire" is, presumably, Sir Keir Starmer (his Wikipedia page was repeatedly edited at the end of last year to remove the world "millionaire").

'A town outside London'

The "landlord" could only be a reference to Emily Thornberry, who has come under fire in the past for her property investments.

The "posh school" reference is harder to pin down - Jess Phillips and Sir Keir went to state grammar schools, but none of the contenders was privately educated.

Thornberry and Starmer are the leadership hopefuls most often forced on to the defensive over their roots.

In the most recent example, an exasperated Sir Keir began referring to himself in the third person in a BBC interview, declaring: "Keir Starmer grew up in a town outside of London."

Image copyright Getty Images/PA Image caption The six contenders are likely to be whittled down to a smaller field on Monday when MP nominations close

There is nothing particularly privileged about his background in Reigate, a Surrey commuter town. His father was a toolmaker and he was the first in his family to go to university, as he is always quick to point out. He is even named after the first Labour MP - Keir Hardie, a cloth-cap wearing, working-class hero.

But he is clearly sensitive about the impression that, as a north London MP and one of the country's leading barristers, he is a member of the hated "metropolitan elite".

The former director of public prosecutions was knighted in 2014 for "services to law and criminal justice" but prefers not to use his title.

'Scraping the barrel'

Ms Thornberry is also titled, by virtue of being married to High Court judge Sir Christopher Nugee, but prefers not to be called Lady Nugee.

"I have never been a Lady and it will take a great deal more than being married to a Knight of the Realm in order to make me one," she said in 2018.

She hits back at claims she is not working class enough by pointing out that she grew up on a council estate, and is the daughter of a single mother.

All true enough, although her father, Cedric, who abandoned the family, was an international law lecturer who went on to be the assistant director general of the United Nations.

Mrs Long Bailey has also faced accusations of exaggerating her working-class credentials.

She may have worked in a pawn shop and at call centres before entering politics, but she also had a successful career in law (not unlike Thornberry and Starmer, perhaps).

Middle-class membership

She said on her election leaflet that she grew up watching her father Jimmy "worrying when round after round of redundancies" were inflicted on the Salford docks where he worked. The docks closed when she was just two.

The Salford and Eccles MP has accused critics who have pointed this out of "scraping the barrel", adding that her dad had also faced the threat of redundancy at his next job.

Image copyright Getty Images Image caption Labour's first MP Keir Hardie is seen as a working-class hero

Birmingham Yardley MP Jess Phillips, was accused of "playing the working class card" by controversialist writer Brendan O'Neill, who claimed her parents had "'unbelievably plush, well-paid jobs".

It prompted her ex-teacher father, Stewart Trainor, to hit back by saying: "Jess knows, and lives for, hundreds of working-class people. They are her people as they are my people - we Brummies are very close."

Another Labour contender, Wigan MP Lisa Nandy, the daughter of an Indian academic, has also talked up her ability to win back northern seats because she "understands the lives" of those living there.

And Norwich South MP Clive Lewis has made much of his working-class roots, speaking at the launch of his campaign about his "socialist and trade unionist" father, who worked in a food-processing plant in Northampton.

But there is scant evidence that being "working class" is an advantage when it comes to winning Labour leadership contests or, indeed, general elections.

Of the three Labour leaders who have managed to win general elections since World War Two, only Harold Wilson could claim to have risen from humble beginnings. Jim Callaghan and Neil Kinnock were working class and proud of it, but they never won power. Jeremy Corbyn came from a middle-class background but, like Kinnock, lost two elections.

Research suggests Labour's membership, who will select the next leader, is predominantly middle-class, although more working-class than it was during the Blair years, and more working-class than the Tory or Lib Dem membership.

A report last year by Queen Mary University of London found that, despite Tory, Labour, SNP and Lib Dem members being more middle-class than their party's voters, they were all somewhat reluctant to describe their party as "middle-class". Labour and SNP members were the most reluctant.

Labour's 'red wall'

"Class is, to some extent, in the eye of the beholder," says Prof Tim Bale, one of the report's authors.

"There are more people who describe themselves as working-class than are objectively working-class."

Image caption James Callaghan (left) and Harold Wilson (centre) were from working-class backgrounds

One reason class is such an issue in the Labour leadership contest is Labour's heavy losses to the Conservatives in its traditional northern English heartlands.

The party also lost seats in Wales and Scotland - but it was the shock of iconic seats like Bolsover, domain of Dennis Skinner, or Tony Blair's former stronghold of Sedgefield, going from red to blue for the first time that grabbed all the headlines.

Much of the focus in the Labour contest so far has been on whether the candidates have got what it takes to rebuild this so-called "red wall" of Labour.

But, argues Prof Bale, "it is incredibly reductive to think that only a working-class northerner can do that.

"I don't think there is any evidence to suggest that the leader has to tick either of those boxes. It is more about their personality than their demographic background."

Working-class southerners

Perceptions of the working class, among the political classes at Westminster, often seem to revolve around "incredibly outdated" stereotypes, he adds.

"There does seem to be an elision between 'working class' and 'northern' as if the two things are the same. It is as if being from the South of England and working class doesn't count."

Image caption Middle-class Tony Blair represented a northern working-class constituency

But "there is a much bigger problem with working-class representation across the entire political class", he adds, which would include the media and academia.

It is, arguably, a bigger problem for Labour than the Conservatives, because Labour was set up to represent working people.

But the Labour leadership contenders are, for the most part, products of a time when the vast majority of MPs are drawn from the professional, rather than the manual labouring, classes.

And, like most MPs, and most of those in public life in general, they can come across as if they have "nothing to say to working-class Britain, which doesn't sound like them and doesn't look like them", argues Tim Bale.

'Looking down their noses'

This is a point echoed by Chris McGlade, who recently wrote about his decision to vote Conservative for the first time in his life on the left-wing, anti-EU site Full Brexit.

"They don't speak with our voices any more. Working-class people, in the main, don't identify with what these middle-class, progressive liberals have to say," he says.

McGlade, a native of Redcar, on the north-east coast, has spent decades working as a comedian on the northern working men's club circuit, but is now breaking through into the distinctly middle-class world of alternative comedy with a show, Forgiveness, about the murder of his father.

As a former Labour member, whose family is steeped in socialist values and traditions, he is the kind of voter the party needs to win back.

But as someone who voted to Leave in 2016, he is angry about Remainers "looking down their noses at us - they consider us to be thick or racist" - and the decision of the town's former Labour MP to back another referendum, in an area that voted heavily for Leave.

"I could not vote for an MP who ignores me. It's about democracy," he says, even though his grandfather would be "spinning in his grave" to see him vote Conservative.

Image caption Redcar went from red to blue for the first time in December

He thinks the background of those standing for the Labour leadership does matter - and that they should come from the communities they are seeking to represent - but it is also about their values and attitudes.

"Of course diversity is important. Of course equality is important. But on the shop floor, in everyday working-class lives, where people are struggling to get by, people are too bothered about feeding themselves today.

"Labour has become obsessed with identity politics and it doesn't feature in working-class life and that is where it is breaking down."

Redcar elected a Conservative MP for the first time in its history in December, on a massive 15% swing away from Labour, in a pattern that was repeated in seats across the North of England.

Jeremy Corbyn never managed to unite the better-off, university-educated, mainly Remain-voting Labour membership with its traditional working-class, mainly Leave-voting support base in its traditional heartlands. It will fall to his successor to rebuild that coalition in a post-Brexit world.

Chris McGlade says he does not hold out much hope for the Conservative government, or believe that they "really care about our class".

"I hope they deliver, but I am not holding my breath. If they don't deliver, I will go back to voting Labour."