A top assistant to a Univisión news boss trashed Sen. Marco Rubio on his aide’s Facebook page, calling the Republican lawmaker a “loser” and “a token slave boy.”

It’s the latest attack in a lengthy feud between the Florida senator and the powerful Spanish-language network that conservatives charge is anti-GOP and anti-Rubio.

The latest incident began Wednesday night after Rubio’s spokesman, Alex Burgos, announced the high-profile Florida senator would give the GOP’s first-ever bilingual rebuttal to President Barack Obama’s State of the Union speech.

That led Univisión employee Angelica Artiles to let loose a string of partisan criticisms.

“Oh. wow, the loser is going to speak after our President,” Artiles wrote on spokesman Alex Burgos’ Facebook page at 9:33 p.m. Wednesday. “Anything to get publicity. Ask him to do us a favor and stay home that night.”

Sentiments like that reflect the prevailing political feeling among Univisión’s higher-ups at its Doral headquarters, say Univisión insiders. Artiles is executive assistant to Daniel Coronell, Univisión’s vice president of news.

The network is owned by a major Democratic donor who has accused Rubio and other Republicans of having an “anti-Hispanic” stand on immigration that’s “despicable.”

In August, someone used Univisión’s official Facebook account to attack Rubio during the Republican National Convention in Tampa.

“Beyond his ideology, Rubio is a mediocre politician who contradicts the values he says he represents. Jeb Bush is more Latino and talented than him,” the Facebook posting said.

When first alerted by the website BuzzFeed, Univisión announced it struck the statement and replaced it with a statement in Spanish that said: “An unpleasant comment not authorized by Univisión News was posted on this page. That comment does not represent the views of Univisión News and we have taken steps to ensure that this situation does not happen again.”

And a year before that Facebook incident, Rubio clashed with Univisión’s news chief, Isaac Lee, when his news team decided to run a story about a quarter-century-old drug bust involving the senator’s brother-in-law.

Univisión began reporting the drug-bust story after Rubio rebuffed repeated interview requests with the network, which had been critical of Rubio’s opposition to liberal immigration policies that Univisión personalities have promoted.

Univisión insiders and Rubio staffers told The Miami Herald that Lee offered to soften or kill a story about the drug bust if the senator cooperated with the network by sitting down for an interview. Rubio refused. The story about the drug bust ran on its national news broadcast.

Lee denied offering a quid pro quo. He wouldn’t speak with The Miami Herald for its original piece, and instead issued a statement.

But after the report, Lee sat down with the New Yorker and admitted he did offer “options” to Rubio’s staff, including Burgos, concerning his cooperation.

For this latest tussle, Burgos refused to comment.

Artiles didn’t return an email, calls or a text message. Her Facebook account appeared inactive and she deleted her comments on Burgos’ Facebook page, but not before others copied them and sent them to The Miami Herald.