Natalie Haynes: You want to act but your parents aren't loaded? Forget it

The thing is that acting, like so many other media careers, has become one which you really need to be rich to pursue. Rob James-Collier, the boo-hiss footman Thomas in Downton Abbey, and star of the new ITV romantic drama, Love Life, has declared what many already knew to be true: that posh actors have it easier because, at the beginning of their careers, actors have to work for so long without money.

Acting is a vile job that has only about 10 per cent of its workforce actually working at any one time. A few reports of vast pay cheques to Hollywood superstars, and everyone believes acting is fun and remunerative. The reality is that if you don't have wealthy parents to keep you in the early years of your career, you may well never get to the later ones but will simply give it up. It's not an issue of laziness, as most under-employment is now considered. Actors always want more work. They will do Fringe theatre or short films or sketch shows unpaid, for months on end, just to build up their showreels or acquire their Equity cards. On top of that, they can and will do all kinds of other jobs to sustain their dreams: James-Collier worked as a bricklayer to keep himself afloat in the early days.

But actors are lucky to receive a day's notice for a casting: skip out of a job to go and audition, and your employer is likely to hire someone more reliable. Yet if you go into work and miss the castings, then your agent will just stop sending you to them altogether.

About 18 months ago, I interviewed several casting agents, and their complaints were identical: there are simply more actors than they can ever hope to meet or know. Too many kids, one explained furiously, are going to drama school, and there is nothing like the demand needed to employ more than a tiny fraction of them.

James-Collier is, obviously, a success story – he's progressed from minor role to leading man. And he is in no doubt that the difficulty of the early days spurred him on: "Because you've done the horrible jobs, it gives you an even grittier determination to succeed".

But this is the story of the 1 per cent of actors who get to the top of their profession. It's not much help to the thousands of young people heading off to do drama courses in the expectation that they, too, will be one of the lucky ones. For them, a far better bet is to find a not-horrible job that they can do freelance, around auditions. Then if the stage doesn't work out, they're not left with nothing.