The Harrison production opened in London in 1990. Mrs Thatcher almost immediately fell from office. Not even the fiercest advocate of the power of drama would claim this was cause and effect. But the prime ministers who succeeded her, John Major as well as Tony Blair, realised the force of such imagery. A specific attempt must be made to get the sleepers off the streets.
There was, of course, a clear, charitable impulse which should not be sold short. But in London especially, businessmen, shopkeepers and the tourism trade wanted to see the streets tidied up, and the Underground wanted sleepers and beggars out of the Tube stations.
The Rough Sleeper Initiative was launched in 1991. By now, pounds 250m of government money has been spent on hostel places and social work. Yesterday the Prime Minister gave a Christmas-time sales-pitch of his own Government's continuation of these policies. He unwrapped a new study carried out by the Environment Department's Rough Sleeping Unit, headed by Louise Casey. He also confirmed - for he came bearing no new money - that there will be more beds for them and more help for young people leaving council care. Between a quarter and a third of those currently on the streets have been in council care at some point.
So far, so good. But this is a very tangled social knot. The official estimate is that in England, 1,600 people sleep rough every night, between 600 and 700 of them in London. From passing observation, this may seem an underestimate. But compassion should be spiced with toughness. The Salvation Army makes its London soup run after midnight; otherwise it gives food to many people who come into the city centre for the day to beg, before catching the last bus home.
To go back, as Tony Harrison did, to classical comparisons: this is a labour like Sisyphus's, for ever pushing a boulder uphill. In a civilised country, help must be given, but it is help that will never cease to be needed. Many sleepers-out can be wooed into a regular off-street life; others will never be. None the less, Ms Carey's view that soup "is the beginning, not the end", should not blind us to real need. Many of those who sleep rough have deep-seated troubles, including drink and drugs, and they may not want to go anywhere else. They have a lessened life-expectancy, but they do not starve, nor are they short of clothes. The charities rightly see to that.
We can, and we must, help. But it is - as they say - a free country. People, including rough sleepers, and even at Christmas, have a right to go to Hell their own way.