start a hare

start a hare (running)

To raise, introduce, or prompt discussion about a certain topic. The MP was quick to state that he didn't want to start a hare running about the controversial issue ahead of the snap election. He started a hare that got the whole country talking about the implications of the new tax on working-class citizens.
See also: hare, start
Farlex Dictionary of Idioms.

start a hare

BRITISH, OLD-FASHIONED
If you start a hare, you introduce a new idea or topic which other people become interested in. Some work needs to be done before the connection between aluminium and heart disease is proved, but Mr Birchall has started a hare that many researchers will be watching. Note: To `start' a hare means to disturb it and cause it to leave its hiding place, so that the hounds start chasing it.
See also: hare, start
Collins COBUILD Idioms Dictionary, 3rd ed.

start a hare

raise a topic of conversation. British , dated
The rapid twisting and running of a hunted hare is here used as a metaphor for the pursuit of a topic in an animated conversation, especially one in which the participants hold strong views.
See also: hare, start
Farlex Partner Idioms Dictionary
See also:
  • start a hare (running)
  • change the subject
  • hold with the hare and run with the hounds
  • run with the hare and hunt with the hounds
  • the talk of the town
  • be the talk of something
  • be the talk of the town
  • air (one's) opinion
  • a sticking point
  • hound