Mr Bebb's resignation from the post came as a shock to many. But is yet another indicator of just how divisive Brexit is.
The Aberconwy MP voted to remain in the referendum. He was highly critical of Boris Johnson's "selfish" decision to quit over Theresa May's Brexit ideas.
And last night his feeling that a hard Brexit would be bad for the nation was stronger than his desire to remain in Cabinet - and so he joined Labour in voting to try to stop a motion tabled by Tory Brexiteers.
But was his decision in vain? His vote did not win lead to a win for Remainers, and now the Ministry of Defence is without a Minister for Procurement just days before MPs break for recess...and before the headlines from the Modernising Defence Programme have been released.
In a department that seems to switch its top team every few months, who will be next up for a stint in the MoD?