42 Man of conviction works hard for Catholics inside (6) - I have seen threads which suggest the answer is contained in the clue, but just can't see it!
It is there you can`t see it because its an obscure word so go through the clue, and try to string two sets of adjoining three letters together and then look them up .
Feel awful now as I cannot find it listed and cannot remember the reference source, will have another look round. Sorry, I do know its a very outmoded word.
Ah, I think it begins with an F and is a French word for a convict, but it doesn't come up easily on Google or my One-look Dictionary search! Perhaps t would if I could add the cedilla!