In an interview, Ajoy Roy from Bangladesh confessed that in late 1930s Punjabi were secular but we Bengali induce them to oppose Hindus.
http://e.dunya.com.pk/detail.php?date=2013-02-28&edition=LHR&id=199002_94303072
his interview published in the left journal awami jamhori forum http://www.ajfpk.org/show-art.php?artid=&bname=AJF-43&type=Art%2011&image_id=1
has revealing story about politics during 1930s/40s.
http://dunya.com.pk/index.php/special-feature/2013-02-28/2524#.US8yD0r-aho