Stories by Welshman in these papers (7)
I believe the answer is:
dailies
'these papers' is the definition.
(daily is a kind of paper)
'stories by welshman' is the wordplay.
'stories' becomes 'lies' (I've seen this before).
'by' means one lot of letters go next to another.
'welshman' becomes 'dai' (I've seen this before).
'lies' put after 'dai' is 'DAILIES'.
'in' acts as a link.
(Other definitions for dailies that I've seen before include "employed in cleaning?" , "Rags" , "Newspapers" .)