IDIOMS

horsetrading

(idiomatic) Informal negotiating, especially when complex or clever in nature.

Example: 2012 September 20, Andrew Brown, “Archbishop of Canterbury succession race begins in earnest”[1], The Guardian (online):
  Next Wednesday, four women and 15 men on the Crown Nominations Commission will gather for two days of prayer and horsetrading to replace Rowan Williams as archbishop of Canterbury.