Aspiration and perspiration are one and the same thing. Labour MP Sadiq Khan, a prospective candidate for the Mayor of London, has urged the competing leaders for the leadership of the Labour Party to lay off going on about aspiration. Khan knows all about aspiration, having risen through the ranks: bus driver father and seamstress mother, and one of eight children.
Aspiration was a problem for his former leader Ed Miliband. Ed and I were on a TV show a little time ago and I was banging on about social mobility - I called it aspiration with attitude - being the best cure for poverty. Miliband told me that mobility wasn't everything. That giving people support while in need was just as important. So a few years before Sadiq Khan was warning the prospective Labour leadership contenders to cool it about aspiration, his leader was warning me against an over-emphasis on aspiration and perspiration.
Certainly Khan perspired a lot in his climb out of straitened circumstances into the middle class. And he lived uncomfortably in the process, even sleeping in a bunk bed in a crowded bedroom so that he could save money for a deposit on a flat or house. He did what was classically called 'burning the candle at both ends', yet he does not want the next leader to go on too much about aspiration and its accompanying perspiration. Even though it was the making of him.
There is a real problem for the Labour Party over aspiration and social mobility - and it goes to heart of the major fault lines that exist in its founding.
Just over 100 years ago the Labour Party was built by trade unionists, Methodists with a heart and conscience and some very well placed former members of the Liberal Party. Essentially, it was a coming together of working men and women driven into politics through the trade union movement, and disenchanted liberals of the middle classes.
The late, lamented Anthony Wedgwood Benn - more comfortable as the prosaically named Tony Benn - came from generations of wealth; you could never describe him as being 'aspirational', in the same way as the bus driver's son Sadiq Khan. Yet they meet in the Labour Party, the supposed party of the working class.
Tony Blair, public school boy and old Oxonian, was another of the privileged members you were likely to run into in the party of the labouring masses. Once again you could never describe Blair as aspirational and socially mobile, for much of the outcome of his rise to prominence could be predicated by the degrees of privilege he enjoyed.
It's a real problem for the Labour Party to keep its identity as the party of the under-represented, especially, as often happens when the under-represented get the chance, they get out of their former social serfdom and morph to Toryism. Added to that, there is a contemporary call from Ukip for former supporters. The base shrinks as the traditional working class lose their former social separation. They begin to participate in the spoils of life formerly reserved for those who used to be seen as their social betters.
One should not forget those people who cannot rise out of poverty and into independence. And Ed and Sadiq in their comments certainly want those who are left behind NOT be left behind when it comes to sharing out the largesse readily available to the socially mobile.
But it is extraordinarily difficult to believe in those who have made it up the greasy social poll through their perspiration to then say it's no great shakes this social mobility.
Those who have done such steadfast work in raising themselves from need - the Diane Abbotts, the Sadiq Khans of the parliamentary Labour Party - should be banging on about aspiration until the cows come home.
It seems to me that the Labour Party has not spent enough of its time debating, encouraging and fighting for social mobility, but has left the whole aspirational charabanc to be captured by the Tories. They left it to David Miliband and others to suggest that aspiration got a bum rap in the recent election with regard to Labour's election promises.
Where are the fights and squabbles, the game-planning to help lift those in abject poverty into the social class that Sadiq Khan and Diane Abbott and their compatriots inhabit? Where is their anger at the paucity of university students who come from a social security background?
Is it not suspiciously like a case of giving the poor a hand out but not a hand up? It smacks of not seeing the poor as their social equals, but rather as members of another species.
The Labour Party needs to bang on about aspiration, about social mobility, because most of those who didn't arrive with a silver spoon in their mouth came with the drive and perspiration to get out of the realms of need. Labour's role models should be those like Abbott and Khan who have climbed so high yet from such limited beginnings.
Khan should be encouraging the growth of the escape routes out of poverty which he took. And not suggesting that there should be less talk of it (hopefully you are not for more social security warehousing outside of opportunity and hope, Mr Khan!)
There is also something to be said for trade unions, that great social increaser. Alan Johnson, a man who could have lead Labour, came through the union movement. Trade unions have been the backbone of, amongst other things, a way of providing members with social mobility. Unions have provided MPs, members of the House of Lords, lecturers and a whole host of professional jobs for union officials and for the official's families.
Unions have helped to swell the ranks of the middle classes, and yet one never hears social mobility and aspiration bandied around much in their work. Surely joining the Labour Party or a trade union must be seen as one of the only opportunities certain people will get to getting on in life.
The Labour Party and the trade union movement have a proud record of helping the aspirational. They should be making more of it, not less if it.
And Sadiq Khan should be celebrating the social elevation that aspiration and perspiration brought to his life. Without it he would not be a prospective candidate to replace Boris. And we, the public, would not have been able to decide on his merits, or otherwise in the forthcoming mayoral race.