Why is Southampton like Pluto?
Pluto is now not a planet and there are 8 planets. Southampton is not a core city and there are 8 core cities.
There have been debates about the relative sizes of Birmingham and other cities. The facts are:
The eight largest English cities outside London are Birmingham, Liverpool, Leeds, Sheffield, Bristol, Manchester, Leicester and Coventry.
The eight largest English authorities outside London are Birmingham, Leeds, Sheffield, Bradford, Liverpool, Manchester, Bristol and Kirklees.
This is because the definition of urban area and authority can be somewhat different.
Both Glasgow and Edinburgh would feature in the list of cities and urban areas if they were included.
Newcastle and Nottingham, however, are core cities. Leicester and Coventry are not.
No idea why.