" The Speaker is the chief officer and highest authority of the House of Commons and must remain politically impartial at all times. The Speaker also represents the Commons to the monarch, the Lords and other authorities and chairs the House of Commons Commission"

The above is the role of the Speaker of the UK Parliament, Over the last couple of years and no doubt before that Mr Bercow has shown he is not impartial is either side of the house. The out an out rudeness in the way you speaks to members of the chambers, the way he treats members of staff (reported in the papers). 

It is time Mr Bercow was made to step down.