The Girl in the Cafe (2005)

Bill Nighy is captivating and Kelly Macdonald is charming

in this offbeat romance, set amidst world politics.

The film tells the story of Lawrence (Bill Nighy), a civil servant working for the Chancellor of the Exchequer (Ken Stott), who falls in love with Gina (Kelly Macdonald), a young woman whom he meets by chance in a London café. Lawrence takes Gina to a G8 summit in Reykjavík, Iceland, where she confronts the Prime Minister of the United Kingdom (Corin Redgrave) over the issue of third world debt and poverty in Africa, much to Lawrence's embarrassment and the anger of his employers. However, he realises that she is right and tries to help persuade the Chancellor and others at the summit to do something about the issues concerned.
IMDb, BBC

Not a period film but one that had me riveted.