light the blue touchpaper

Meanings:

• 1.

  UKBritish Englishinformaljournalistic
  • To initiate an action, remark, or event that is likely to provoke a rapid, lively, or volatile reaction.

• 2.

  UKBritish Englishinformalfigurative
  • To set in motion a process that is expected to escalate quickly or to produce noticeable effects.