By Brian Wheeler
Political reporter, BBC News
Class is back. Politicians have spent the past decade or more telling us we live in a classless society. Even that old class warrior John Prescott claimed "we are all middle class now".
Class politics has become 'deeply unfashionable' on the left
But in the past few weeks the class war has been reignited with a vengeance.
Labour's deputy leadership contenders started it.
Like the Yorkshiremen in Monty Python's famous sketch ("You were lucky to have a lake... There were a hundred and fifty of us living in t' shoebox in t' middle o' road"), the deputy hopefuls have been trying to out-working class each other.
Former postman Alan Johnson, brought up by his sister after his mother's death, has repeatedly described himself as "someone whose background, foreground, mainland and hinterland are working class".
SELF-ASSESSED SOCIAL CLASS
Middle class: 28%
Working class: 66%
Neither/don't know: 5%
Middle class: 32%
Working class: 61%
Neither/don't know: 7%
Middle class: 40%
Working class: 57%
Neither/don't know: 3%
Source: Ipsos Mori
Hazel Blears - described by her campaign literature as a working class Salford girl whose father was a fitter and lifelong trade unionist - rarely misses an opportunity to mention her bus driver brother.
Jon Cruddas, a comprehensive school-educated son of a sailor, has even said it is impossible to talk about Labour's future without mentioning the c-word.
"A return to issues of class is central to this debate, yet discussion of class remains deeply unfashionable within the party," he wrote recently in The Guardian.
Then the Conservatives got in on the act with an almighty row about that most class-ridden and quintessentially British of all subjects - grammar schools.
Strip away the policy detail, and for many grassroots' Tories the row boils down to one issue - how can David Cameron, of Eton and Oxford, presume to deny middle and working class parents the selective education he enjoyed?
"It looks as though he is completely out of touch with those who don't have the money he has," said former Tory MP - and self-confessed 11-plus failure - Michael Brown.
"I think there is an element of class war within this.
"And I certainly think that the ordinary party workers in the constituencies and ordinary backbench MPs who haven't had David Cameron's privilege do feel that he doesn't understand what it is that motivates middle class parents," Mr Brown told BBC News 24.
Mr Cameron simply argues that those who yearn for a return to grammar schools are suffering from a particularly "deluded" form of "bring backery" - and that academic selection has been shown to do nothing to improve social mobility.
Whenever the subject of his own privileged background comes up, he simply turns the class issue on its head, arguing that where you come from is not nearly as important as where you are going.
Is he right? Does anyone in the real world, outside Westminster, care about class any more?
Or have new class boundaries sprung up to replace the old ones?
In purely economic terms, the gap between those at the top and those at the bottom of the income scale has rarely been greater.
"Inequality still remains high by historical standards - the large increase which took place in the second half of the 1980s has not been reversed," the Office for National Statistics said in its annual study of wealth distribution.
And - according to a recent London School of Economics report disputed by the government - social mobility is grinding to a halt.
But at the same time, the middle class has grown in size and the closure of traditional heavy industries has sounded the death knell for the traditional working class in many areas.
Dr Roger Mortimore, of Ipsos Mori, said: "The one crucial thing that has changed is that, in real terms, the working class is much smaller than it used to be.
"For Labour to win an election it is not enough for them to win working class votes. They have either to tone down the class rhetoric or make an effort to appeal to middle class voters."
But although in purely economic terms, the middle class has grown in size, more than half the still population thinks of itself as working class, according to research done at the time of the 2005 general election by IPSOS Mori.
And "self-assessed social class" still has a bearing on how people vote.
"Aspirational" working class people - those in manual occupations who consider themselves middle class - are still more than twice as likely to vote Tory, according to IPSOS Mori's research.
The Conservatives managed to attract these voters in the 1980s, with policies such as tax cuts and the sale of council houses to their tenants.
The problem, for the Conservatives, is that there are now not so many "middle class" C2DEs, as they are classified by market researchers, left.
But there an awful lot of ABC1s, people in middle class professions, who consider themselves working class and, therefore, vote Labour, the research suggests.
By this logic, Labour could afford to play the working class card more often, argues Dr Mortimore in his 2005 report on voting behaviour, while the Conservatives could win votes by playing up their middle class credentials.
Or they could both ignore this complex and contradictory issue altogether in the hope it will go away again...