We all agree dropping litter is wrong, but... then what's next?

If more of us were to embarrass detritus-leaving louts maybe we would keep the rats off our streets

The well-dressed woman on her way to The Nutcracker last week looked old enough to know better. With grandchildren in tow, she inspected any small flat surfaces outside the theatre, carefully balanced her McDonald's fries carton on a window ledge, and went in to enjoy the music of Tchaikovsky and pretty dancing in the Land of the Sweets, where vice is trounced and virtue rewarded.

This way of discarding litter – not dropping it, you understand, but placing it – has become almost standard practice, as if leaving the takeaway cup or wrapper alongside others on a piece of street furniture constitutes disposing of it responsibly. The truth is, rubbish that is placed is merely litter in a high place, waiting to fall.

When challenged, the ballet-lover explained that she had been "looking for someone to give it to". Now, even in the exaggerated world of the dance, there is not, as far as I can recall, a society in which one group of people stands around waiting to be handed the detritus of another.

This is the same warped world in which resides the man who balanced his cup on the ironwork of Tower Bridge: he told me that people are employed to clean up after him. In a sense, this is true; but the City of London, which spends nearly £4m a year on street-sweeping, would, like any local authority, surely prefer to spend that money on hot meals for old people.

Raging against litter is like fuming over misplaced apostrophes, the use of "like" for "as if", and younger actors whose voices go up at the end of sentences in costume dramas. Mention of your obsession will invariably be met with total agreement. No one ever says they prefer the streets strewn with sauce, bones and packaging, any more than they choose to buy potato's. But is it enough to mind and not act?

Picking up litter in your own neighbourhood may not look cool, but it not only means the street is clean several days before the professionals come round, but it also makes littering less of a foregone conclusion. Nothing attracts litter like litter; where one cup is placed, a dozen follow. Interrogating those who place litter invites invective, but the foul language only masks embarrassment, and being unassailably right about public hygiene acts like Teflon. Yes, it gets tedious explaining, yet again, that the street is everyone's shared space and that the deal is this: if your latest victim stops leaving rubbish in your road, you won't go round and drop chips on his bed.

The semiotics of litter vary from culture to culture. In Behind the Beautiful Forevers at the National, a whole community lives in the shadow of Mumbai airport, sifting trash to make a meagre living. No grot, no dinner. In Sicily, where the mafia nails lucrative contracts for rubbish collection, festering heaps signal a falling-out, and individual efforts to keep the kerb clean are lost in a tide of filth that is a metaphor for the whole sorry system.

In Britain, between the consumer who walks away from a coffee shop with handfuls of litter-to-be and the environmental health department of the local authority, rear the multinational giants whose profits are as overwhelming as their indifference to the problem they have created. Down my way, Starbucks produces the most litter, although the new Pret is catching up fast. Pizza outlets present a different menace, because the boxes are too big and too sturdy to be easily folded and binned, so they are stacked beside bins, as if propping litter were not the same as dropping litter.

A small building firm that does a job in the home has to pay to discard associated rubble, but Starbucks and allies simply leave the council to pick up the tab. They could offer to pay for bins. They could remind their customers that littering is a costly offence. They could send staff out to litter-pick. They could operate a deposit and money-back scheme for cups. They could stop charging more to eat in, where there is recycling, than for takeaway, where there is none. At least the Government is stepping in at last, and not before time.

Listen up, Starbucks: you make the litter, you take the litter.

When, some years ago, dog-fouling was a massive problem in this country, there were rumblings about getting dog-food companies to take some financial responsibility for the mess they were indirectly creating. Today, there is an almost universal acceptance that owners must clean up after their dogs, pretty much based on that reliable deterrent, shame. Now we are never more than 10ft from a litterbug. I suggest the balletomane take the fries box home next time. Otherwise she, and we, are going to find that the Mouse King and all the other six-foot rodents are no longer on stage but running fatly down the street.

Hamish McRae is away