Not just Corsas, but all Vauxhalls of that age. Particularly bad after heavy rain. Either the brake dust makes a sort of glue, or the shoes and drums are corroding themselves together as in this link.
http://htdig.honestjohn.co.uk/faq/faq.htm?id=8 8
However in my experience a really bad attack usually leads to the discovery of a leak from the brake cylinder and brake fluid getting involved.
To get it moving you have to select reverse and keep rocking it violently backwards and forwards. It releases with a bang. If you call out the AA they will climb underneath with a mallet and thump the drums hard.