Liberal Democrat minister Norman Baker quit his Home Office job this week, citing a strained relationship with Theresa May.
Theirs was not the first cross-party double act to come under strain. But Conservative ministers and their Lib Dem colleagues are not always at odds...
George Osborne and Danny Alexander (Treasury)
Mr Alexander (pictured above with the chancellor) joined the Treasury after David Laws’s expenses scandal. The chancellor probably thought he would be too left-wing to fit in, but there has been no sign of tension.