A new government study reveals that the "centre of gravity" of the British population has been moving south-eastwards since 1901 - and now lies a few hundred yards outside the village of Overseal, south of Swadlincote on the Leicestershire/Derbyshire border. But the drift,the study suggests, accelerates under Conservative governments. At the height of Thatcherism, the centre moved south-east faster than at any time since the Depression of the 1920s, as Northerners followed Norman Tebbit's call to "get on their bikes".
The investigation, carried out for the Office of Population Censuses and Surveys by Newcastle University, has plotted the centre of Britain's population throughout this century. This shows the point where the populations north and south, east and west, are evenly balanced, with a weighting for distance so that somebody living in the Scottish Highlands, say, would count for more than somebody living in Sheffield.
While the United States makes a major feature of its centre of population, moving a special wooden post across the country to mark the spot each year, this is the first such survey in Britain.
It found that the "point of balance", at the hamlet of Rodsley in Derbyshire in 1901, has since moved 16 miles south-east. Dr Daniel Dorling, a co-author of the report, says that while this may seem a short distance it is in fact a "dramatic" change for a country as long-settled and densely populated as Britain.
He says the biggest shift - nearly three-and-a-half miles - took place in the 1920s. The drift continued in the Thirties. It probably stagnated during the war, but regained speed in the 13 years of Conservative rule in the Fifties and early Sixties.
In the Seventies the shift halted again, with the "centre of gravity" zig-zagging through the suburb of Newhall in Swadlincote; but after Margaret Thatcher came to power in 1979"the steady move south began again in earnest". In every year between 1983 and 1988 the move seems to have been greater than at any time since the Twenties. It has slowed down in the recession. Dr Dorling attributes this partly to the house price slump, which has made it harder for people to move, and partly to the fact that "there are no jobs to go to in the South".
Another reason for the recent shift appears to be membership of the European Union, as the population of countries on the periphery of Europe is increasingly moving towards its centre. Northern Italy and Barcelona, for example, are both growing at the expense of the rest of their countries.
The report expects the south-eastern shift to continue. It concludes: "If current rates continue, the population centre of Britain would hit the South Coast at Worthing in 2771."