And it was pretty plain from the contributions to Defence Secretary Geoff Hoon's difficult Commons statement on the issue on Monday that they are ready to defy the prime minister over this "step too far".
The government is not blaming FirstGroup, but implicit in the minister's statement is that FirstGroup's risk projections were either over-ambitious or just plain wrong.
Lord Goodhart told the BBC that what was "certainly unfortunate, to say the least, is that there is what seems to be a plain inconsistency between what Margaret McDonagh told us in the Neill Committee and what, according to the latest statement, appears to be the case".