Bernie Sanders is attempting to wage a fight to the finish for the Democratic presidential nomination -- and to upend the party’s “rigged” system -- by trying to remove key convention officials.

The Sanders campaign has called former Massachusetts Rep. Barney Frank and Connecticut Gov. Dannel Malloy “aggressive attack surrogates” for Democratic presidential front-runner Hillary Clinton.

And it formally requested that Frank and Malloy be removed as co-chairmen, respectively, of the Rules and Platform committees at the Democratic National Convention.

The Democratic National Committee on Saturday rejected the request, saying Frank and Malloy were elected under party rules and that Sanders wasn't alleging any violations of that process.

Frank and Malloy have been “aggressive attack surrogates for the Clinton campaign,” Sanders campaign counsel Brad Deutsch wrote in a letter Friday to the party leaders. “Their criticisms of Sen. Sanders have gone beyond dispassionate ideological disagreement and have exposed a deeper professional, political and personal hostility toward the senator and his campaign.”

The committees are two of the three most-influential committees at the convention in July, helping shape the party’s agenda and message for the general election into November. The other committee is the credentials committee.

“Two of the three Convention Standing Committees are (apparently) being constituted in an overtly partisan way designed to exclude meaningful input from supporters of Sen. Sanders' candidacy,” the letter also stated.

Sander and his supporters from essentially the start of the primary season have accused Democratic National Committee Chairman Debbie Wasserman Schultz and others in the party of playing favorites with Clinton, the establishment candidate.

Sanders says Wasserman Schultz limited the number of primary debates to protect Clinton.

Under party rules, Wasserman Schultz also made roughly two dozen appointments to the three committees.

Meanwhile, Sander supporters allege party leaders have manipulated the process by which delegates are appointed to the convention, creating chaos over such concerns earlier this month at the Nevada state Democratic convention.  

Sanders continues to stay in the primary race, despite facing very long odds of winning the nomination. And while party officials seem eager for Sanders to drop out, the self-described democratic socialist continues to try to win delegates in the few remaining state contests to try to exert some influence over the party platform being rolled out at the convention.

“Clinton received the support of over 400 super-delegates before anybody else announced for the race. That’s called an anointment,” Sanders said in a recent Time magazine interview, arguing about an unfair primary system.

“It is clearly undemocratic. It is a way for the establishment to push their candidate forward.”

Even presumptive Republican presidential nominee Donald Trump, albeit with the likely motive of hurting Clinton’s campaign, has come to Sanders’ defense.

“The Democratic nominating process is totally rigged and Crooked Hillary Clinton and Deborah Wasserman Schultz will not allow Bernie Sanders to win,” Trump said Friday.