From my reading of this, it could also imply an unorganised set of the predatory wealthy all acting within their own self-interest, rather than a conspiratorial cabal.
That such 21st century robber barons are seeking to gain from Brexit is no secret. It is likely this is what the author refers to.
Various reasons, e.g. losing the perceived economic benefits of a free trade zone with the rest of the EU countries.
EDIT:
I can't reply to the comment below for some reason, so here's what I was going to say:
Much of the EU's unpopularity amongst the Brexit-supporting section of the UK's population comes from it repeatedly being used as a convenient scapegoat for domestic political issues, and the country's most-read newspapers printing decades of nonsense ("EU bans yogurt and cheese from school dinners", "EU bans straight and bendy bananas", etc.) that were taken as fact about what a broken institution it is.
Brexit was really just the end result of a spectacularly successful sustained propaganda campaign.