It was Minister of Culture David Lammy who a few years ago praised metal detecting as allowing all those underprivileged social groups (C2s, Ds and Es in modern sociological parlance) who had been previously "challenged by formal education" some kind of hands-on contact with history. This is published in the PAS annual reports as well as the Hawkshead review of the PAS. It was not me that said it.
In 1995 Laura Bushell, Carrie-Anne Brackstone produced a book called “Oi Pikey! A celebration of Cheap Living”,* which characterizes this social group pretty well. They give a list of “pikey pastimes” as including bingo, car boot sales, complaining, DIY, eBay and metal detecting.
* For the non-Brit: "Pikey is a pejorative slang term used in the UK and Ireland […] to refer to a wide section of the (generally urban) underclass of the country, particularly those on whom the lower middle classes look down [...]"