Five major television networks sent a letter of protest to the South Carolina Democratic Party over the party's decision to grant exclusive live television coverage of its convention Saturday.

Officials from CBS, ABC, C-SPAN, Fox News and CNN sent the letter Thursday to formally protest the deal, which forbids the networks from broadcasting or livestreaming any footage of the 22 presidential candidates expected to appear Saturday until three hours after the convention is over, even on social media.

South Carolina is a key state in the presidential nominating process and will be the largest gathering to date of the Democratic hopefuls, making this weekend's event important to potential voters, the spurned networks said in the letter. The networks say the decision would limit access to news and could set a bad precedent for other states.

"The political parties have always had a tradition of open media access," the letter says. "Your decision to restrict live coverage of your state party convention to a single news organization is the antithesis of openness. It is also concerning in that it could set a precedent that would end up seriously limiting citizen access to other key presidential electoral events."

The letter was addressed to Trav Robertson, SCDP Chair.

No reply had been received by Friday afternoon, according to an email from Peter Kiley, a C-SPAN spokesman.

Robertson said Friday that the party had credentialed 158 journalists for the convention from 60 media outlets on six continents.

"The denial of access is a fabrication," he said.

The networks hadn't claimed they were denied access, but said in their letter that the event should be made available to "every accredited media outlet without embargoes, restrictions or other limitations."

After criticism earlier this week that the event would only be available live to those who have access to cable television, the SCDP will allow South Carolina Educational Television, the state's PBS affiliate, to livestream the event on its social media platforms.

Initially, the SCDP granted exclusive rights to MSNBC in exchange for the network's significant investment in covering the event, but that decision barred other outlets from covering the event with live. The networks only found out about the limitation this week after many had set coverage plans in motion.

That plan apparently backfired, and by Wednesday afternoon the party had changed course, at least for viewers who can access the convention online.

"This afternoon, SCETV confirmed that it will livestream Saturday’s convention on the station’s YouTube and Facebook channel/page," said Jeremy Cauthen, SCETV communications director, said Wednesday.

SCETV also plans to livestream the popular fish fry hosted by U.S. Sen. Jim Clyburn on Friday night.

No money was exchanged in the agreement to grant exclusive live coverage to MSNBC, said Robertson.

“At no point has the Democratic Party been paid by any news outlet to cover a convention,” Robertson said early Wednesday.

The party made the agreement with MSNBC because the cable channel planned significant coverage of each of the candidates and planned to have interviews with candidates on the Joy Reid Show and the Rev. Al Sharpton Show.

“We spoke to several networks about this, and MSNBC was the network that decided they wanted to move forward with this,” Robertson said. “The fact is that the Joy Reid Show as well as the Rev. Al Sharpton Show have a significantly higher African-American viewership or audience, so it seemed to be a fit for this specific convention.

“But most importantly you’ve got a situation here where every presidential candidate who speaks has got their seven minutes broadcast by MSNBC and then they’re going to do a stand-up.”

Asked why the party would limit live coverage of its convention to one cable outlet, Robertson wouldn't answer, saying only that Fox, CNN and other outlets haven't been barred from bringing in cameras to cover the event and could have rebroadcast rights forever after the event concluded.

"There's no signed document here," Robertson said.

There is, however, an email sent to credentialed media that says in bold print that MSNBC has the exclusive live rights to broadcast the convention, and "any footage of the convention taken by other outlets may not be aired live, and is EMBARGOED FOR THREE HOURS after the close of the convention." The words "embargoed for three hours" are in bold red font.

"We would like for the organization that said 'We're going to come in and cover all of our candidates running for president' the opportunity to have the investment that they've made with this," Robertson said. "Yes, they should have an opportunity with some of that."

He said more than 100 media outlets are credentialed to cover the convention.

"We wanted to create an opportunity that was positive for the people of South Carolina, the candidates who were coming in to South Carolina and, most importantly, an opportunity to make South Carolina shine," Robertson said.

C-SPAN posted the letter on Twitter Friday afternoon.