(CNN) - The Democratic National Committee is challenging MSNBC's decision to allow one of its hosts, Joe Scarborough, speak at a New Hampshire state GOP event.
In a letter to MSNBC president Phil Griffin on Thursday, the committee's communications director, Mo Elleithee, accused the liberal-leaning cable news channel of having a "pretty big double standard" when it comes to host participation at partisan events.
The dust-up comes amid media scrutiny about Scarborough's scheduled keynote speech at the Cheshire County, New Hampshire Republican Lincoln Day Dinner on May 2.
Why, some reporters and activists wondered, was Scarborough allowed to participate when another MSNBC host, liberal firebrand Ed Schultz, was barred from speaking at a local Democratic committee dinner in Florida in March? That dinner was labeled a fundraiser, which led The Huffington Post to inquire about MSNBC's policies regarding partisan events.
Schultz subsequently backed out of the event.
On Wednesday, an MSNBC spokeswoman said of Scarborough's event in New Hampshire, "Joe isn't participating in a fundraiser. MSNBC hosts often participate in events where there is a nominal fee for registration or tickets that basically cover the cost of the event. There has been no change in policy."
Elleithee then chimed in on Thursday morning in a letter to Griffin.
"I don't begrudge Joe participating in this event," Elleithee wrote. "But for the life of me, I couldn't figure out why he would be allowed to speak to a Republican event, but other MSNNBC personalities were not allowed to speak at Democratic events. Seems like a pretty big double standard."
"It appears by MSNBC standards, a fundraising event is not a fundraising event if it does not call itself a fundraising event, even while raising funds at the event (through "nominal fees"). On the flip side, a fundraising event is a fundraising event when it raises funds and calls itself a fundraiser," he continued.
"Now that the policy is clear, we will be sure to advise all Democratic state and local party organizations of this distinction, so that they can be sure to invite MSNBC personalities only to the 'non-fundraising' events, as opposed to the 'fundraising' events."
An MSNBC spokeswoman had no immediate response on Thursday morning.
Scarborough’s co-host on "Morning Joe," Mika Brzezinski, was seated in the audience earlier this week at an Equal Pay event at the White House.