Possible Clues:

• What's put up right to left where right, left and centre put up?
• A vote to select politicians
• Board-choosing activity
• Conservative protected by wicked elite -- no thing a Labour MP wants?
• Having to stand for this, some get cross more than others
• Occasion when politicians try to make people cross?
• Seat can be obtained by this horse bucking head
• Choice of the Spanish division to depose leader
• Start off one process of choosing or another
• House perhaps changing right to left for vote