The gloves are off
Definition 1 of 1
Pro Tip 1/3Metaphorical Conflict
Represents a shift to direct confrontation in arguments or competitions, metaphorically removing protection to fight harder. 
When the negotiation failed, the gloves were off and both sides prepared for a legal battle.
Pro Tip 2/3Informal Expression
Best used in casual or informal settings, not usually suitable for formal contexts. 
In the heated forum discussion, one user commented, 'Alright, the gloves are off now!'
Pro Tip 3/3Emotional Intensity
Implies an increase in emotional investment, as parties become more determined or aggressive. 
The debate was calm initially, but after that comment, the gloves are off.