Scottish workers in the defence industry were warned that voting for independence could cost them their jobs.
The Defence Secretary Philip Hammond said building navy warships in an independent Scotland could cease.
He issued the direct warning to employees at a Glasgow-based firm that their future prosperity, and that of their families, would be put in jeopardy by a Yes vote in September.
But he was told by one member of staff that he appeared to be threatening people in the run up to the referendum.
ITV News' Scotland correspondent Debi Edwards reports: