Possible Clues:

• Explosive material about heads of Labour and Tories
• Ready to explode anytime
• Subject to sudden changes
• Temperamental rodent keeps swishing tail
• Apt to go into a rage
• There it is, heartless, backward, the pick of society for the most part and highly strung
• Mercurial little creature biting curly tail
• Funny oval Scrabble piece that's changeable
• Set off easily
• Sal --, another name for ammonium carbonate