•
Leslie Banks as David Barr •
Carol Goodner as June MacKinnon •
Frank Vosper as Lord Dean •
Alfred Drayton as Manning •
Campbell Gullan as Hannay, a shipyard worker •
Percy Parsons as Casey, one of Manning's undercover troublemakers •
Fewlass Llewellyn as Sir Gregory, a member of the company's board •
Henry Oscar as Raglan, a member of the board •
Allan Jeayes as Grierson •
Donald Calthrop as MacLeod, another of Manning's saboteurs • Henry Caine as Bassett •
George Carney as Mr. Lindsey, a publican (uncredited) •
Jack Lambert as Police Inspector (uncredited) •
John Laurie as Wages Accountant (uncredited) •
Frederick Piper as Mr. McWilliams (uncredited) •
Jack Raine as Testing Official (uncredited) ==Production==