The Governmenty statistics office report states it lies on the Derbyshire/Leicestershire border village of Overseal as of the 1991 census.
Howeverer by 2001 it had moved 6km south to the village of Appleby Parva in rural Leicestershire according Professor Daniel Dorling of the University of Leeds. The center has been moved about 32km south since 1901.
The British Statistics office report remarks, on a lighter note, that if the current rate continues it would hit the south coast at Worthing by 2771.
Manchester has both big city status and claims a type of population based centrality. I took this from the Manchester Commonwealth Games web site:
"As well as having a population of over 400,000, 60 per cent of the population of Britain, more than 33 million people, live within a two hour drive of Manchester. The wider area of Greater Manchester has a population of 2.5 million and comprises the cities of Manchester and Salford and the Metropolitan Boroughs of Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford and Wigan."