You need to intervene effectively to solve this performance issue. You will need to plan and conduct a coaching session with Peter to get both Peter's and the team's performance back on track.

In the session ensure you:

Introduce the session positively by establishing why the coaching is occurring and ask Peter for input:

Ask Peter to describe own performance, personal situation, obstacles to performance, feelings and job satisfaction.

Model emotional intelligence through empathy and listening skills.

Build Peter's awareness of emotional intelligence weaknesses and strengths - make sure you focus on Peter's strengths.

Using the GROW model, establish Peter's goals and performance gaps (reality):

Build Peter's awareness of performance shortcomings and how emotional self-awareness and empathy can help identify personal obstacles to success with Peter's goals, peer relationships and help the whole team and organisation to succeed.

Continuing with the GROW model, establish and discuss reasonable options:

Allow Peter to provide most of the options for reaching personal, professional and team goals.

Continuing with the GROW model, establish Peter's willingness to perform (and increase EI) in measurable and observable ways:

Establish a firm commitment from Peter to improve performance and help build a better team climate.