In an internal memo to talent and EPs obtained by the Huffington Post, MSNBC president Phil Griffin asked his on-air talent not to criticize one another publicly. He acknowledged that the opinions expressed on his network can lead to “spirited, substantive disagreements,” but called the infighting “unprofessional” and reminded everyone that they “are all on the same team.”

We have many strong personalities with differing, passionate opinions, but it is important to remember that we are all on the same team. I want to reiterate my long-standing policy: We do not publicly criticize our colleagues. This kind of behavior is unprofessional and will not be tolerated.

Let me be clear: I encourage you to keep doing what you do best. Give the viewers your perspective and a vigorous debate on the issues they care about. But do not turn substantive differences into personal ones.

The memo was in response to an incident earlier this week, in which Joe Scarborough criticized Keith Olbermann on twitter for his comments about Senator-elect Scott Brown.

> More: Griffin responds to TVNewser, “An important rule was broken. I spoke to Keith and he said in the spirit of teamwork and the free flow of ideas, he didn’t think it warranted punishment or suspension. I also talked to Joe and he apologized to me,” said the MSNBC president, adding, “That’s why I made the decision that this didn’t rise to the level of punishment, but I felt it was necessary to reiterate my long-standing policy.”