This seems to be a bit of a strange one, Balkans.com are reporting that Ryanair are interested in operating flights from Stansted and Prestwick to Podgorica. Apparently the flights are to operate year-round. Details available at the link below..
Balkans.com Business News : Ryanair is likely to begin flights to Podgorica, Montenegro in September
As Montenegrin Airlines have suspended their Gatwick operations, STN makes a bit of sense, but I can't see PIK working year round. Summer maybe as Montenegro is an up and coming tourist destination but would the demand be there?