MSNBC host Ed Schultz has come under fire from his left flank over his alleged lack of solidarity with NBC employees seeking to unionize. Schultz has fired back by claiming his liberal critics have "income envy."

The fight began on Thursday, when reported that Chris Hayes was the lone MSNBC host to meet with a group of workers seeking to unionize at the GE-owned network. A joint petition by the AFL-CIO and Civic Action had asked the cable network's hosts to "please meet with these workers and take a public stand to support their right to organize."

Hayes didn't comment on the meeting though, and several of the cable network's other hosts — Rachel Maddow, Al Sharpton and Lawrence O'Donnell — declined comment as well. They don't appear to have made any comments elsewhere either.

It is an extremely awkward issue for the hosts. On the one hand, they are all avowed liberals with major media platforms who supposedly support organized labor. On the other hand, their employer is opposing the unionization push — the activists have alleged union-busting — and other than Hayes they evidently aren't that interested in sticking their necks out on the matter. None responded to's interview requests.

The exception was Shultz, who emailed Salon's Josh Eidelson: " has never been an ally of Ed Schultz, why should I help you with a story? Give me a reason." After the story was published Thursday, he was criticized by other liberals for the comment.

Schultz defended himself later that same day, saying on his radio talk show (which is not with NBC) that: "If has never been a fan of Ed Schultz, why should I put myself in jeopardy through an email? … I don't need some writer who's got an agenda or wants to pit somebody against somebody else. I've got plenty of platforms."

He later added, "I’m not going to lower myself to people who just have got employment envy, income envy, exposure envy, platform envy." Later in the show he said he was a target because he is "living good."

Schultz also discussed a longtime feud between him and liberal activist David Sirota, a former Salon writer who has criticized the MSNBC host in the past. Schultz called him a "loser" on his radio show Thursday.

Sirota responded, telling Salon: "Only a true narcissist would respond to calls for solidarity by slamming people as 'jealous.'"

That was all just round No. 1. On Friday, Schultz got into a heated argument with another liberal writer, In These Times' Mike Elk, after he called into the radio show. Elk repeatedly asked if Schultz supported the NBC workers' efforts to unionize. Schultz refused to directly respond, instead saying he supported the rights of all workers to unionize. "You're evading the question," Elk said.

It deteriorated from there, with the two arguing first over each others' bonafides as labor supporters and then over Schultz's having received substantial amounts of money from unions to advertise on his website. After the latter subject came up, Schultz again claimed that his critics had "income envy."

"You're accusing me of income envy?" an incredulous Elk asked.

"Yes, I am, because that is all you are talking about," Schultz responded. He then began belittling Elk, calling him "Mr. Big Labor guy."

"Where do you think unions are going to spend their money for advertising? With you? You don't have an audience. You don't have a reach. You've only got 12,000 Twitter followers. You've got income envy!" Schultz said, adding, "Gosh, you're a little quiet all of the sudden."

On his Twitter account, Sirota wrote: "I think this public meltdown is Ed Schultz's Charlie Sheen moment."