Is this the same Filbert who sets puzzles occasionally for the Independent? I assume so, which is why I approached this with trepidation as I've always found Filbert's Indy puzzles very difficult. As it happens, I found some of his Listener clues easier than his Indy ones (!) though this is probably a matter of expectation. As Scorpius rightly says, the misprints were neatly handled and the clues in general were excellent. My main stumbling block was understanding the two thematic clues - because I spent far too long applying them to the wrong entries.
A brief but satisfying, and unambiguous, endgame which I enjoyed. I was surprised by the placing of the thematic object until I watched a clip of the protest which confirmed it was correctly located. And how convenient was its location for the aesthetic quality of the grid!
A fine debut. Did anyone else, I wonder, get the first four letters from the downs and think this was part of a proper name which would lead to a political theme?