I have to beard the lion in his den and ask for a raise.
beard the lion in his den
idiomTo confront an adversary in his or her own environment.
Origin
disputed originFrom sense beard (“to confront”).
She decided to beard the lion in his den by visiting the manager's office to complain about the new policy.
Knowing the director would be furious, the young lawyer steeled himself to beard the lion in his den and challenge the unfair contract terms directly.