Looking to force a contested convention, Democratic presidential hopeful Bernie Sanders' campaign called on party leaders Saturday to remove "aggressive attack surrogates" former Massachusetts Rep. Barney Frank and Connecticut Gov. Dannel Malloy from key DNC panels.

Contending that Frank and Malloy's criticisms of the Vermont senator have "exposed a deeper professional, political and personal hostility," Sanders campaign counsel Brad Deutsch penned a letter to the Democratic Party's Rules and Bylaws Committee asking to remove them as the convention's respective Standing Rules Committee co-chair and Standing Platform Committee co-chair.

Pointing to the former Massachusetts lawmaker and Connecticut governor's surrogate roles with Democratic rival Hillary Clinton's campaign, Deutsch contended that they cannot be relied upon to fairly and capably perform their convention duties.

"The appointment of two individuals so outspokenly critical of Sen. Sanders, and so closely affiliated with Secretary Clinton's campaign, raises concerns that two of the three Convention Standing Committees are being constituted in an overtly partisan way designed to exclude meaningful input from supporters of Sen. Sanders' candidacy," he wrote.

Deutsch argued that Frank has a long-standing animosity toward the Vermont senator, pointing to a 1991 New York Times article in which the former Massachusetts congressman was quoted as saying that he thought Sanders had "unduly denigrated the institution (of Congress) and a lot of the members."

The former congressman, meanwhile, blasted Sanders in a late-March Slate article, as well as in an early February Politico op-ed, the campaign contended.

"The co-chairs of the Standing Rules Committee hold broad power to submit resolutions and measures for vote on the floor of the convention. It is imperative that this power be wielded by someone who respects and is inclusive of opposing viewpoints," Deutsch wrote. "Mr. Frank's barbed remarks toward Sen. Sanders and his supporters demonstrate Mr. frank is not such a person."

Malloy, meanwhile, has said he "'will continue to work hard to make sure [Hillary Clinton] is elected president of the United States this November,'" Deutsch said, arguing that the campaign believes it would influence his work as the Standing Platform Committee's co-chair.

Beyond this, he wrote, Malloy has been an "incendiary critic" of Sanders, drawing comparisons between the Vermont senator and presumptive Republican presidential nominee Donald Trump and blaming him for national gun laws during a late-February stop in Springfield.

Malloy told Clinton supporters who crowded the Student Prince that the so-called "Charleston loophole," a three-day waiting period for background checks, should be known as the "Charleston-Sanders loophole." He, however, noted that he does like the Vermont senator's proposals.

"I like hearing Bernie," the Connecticut governor said. "If I had a magic wand I'd do all the things he says, but he doesn't have a magic wand and nor do we."

Despite this, Deutsch argued that the campaign has legitimate concerns that Malloy's "open animosity" toward Sanders could make him antagonistic to the views of the senator's supporters.

"The foreseeable exclusion of such a large constituency from this process would be damaging not only to the campaign and its supporters, but to the DNC's own efforts to unify the party," he wrote.

Sanders' campaign called on the DNC's Rules and Bylaws Committee co-chairs to disqualify Frank and Malloy or provide a hearing followed by an advisory opinion regarding their fitness to serve in their appointed roles.

If the committee does not address the issue, Deutsch said, the campaign will seek resolution by presenting its objections at the Standing Platform and Rules Committees' initial meetings.

Jim Roosevelt and Lorraine Miller, the Rules and Bylaws Committee co-chairs, in response to the Sanders campaign's request, noted that the DNC Executive Committee elected Malloy and Frank in late-January pursuant to the call for the 2016 Democratic National Convention.

The campaign's challenge, they wrote, "does not allege that there was any violation of the provisions of the call in the conduct of their elections or otherwise assert that there was any other cognizable violation of the call, the delegate selection rules for the 2016 Democratic National Convention or any other rule or regulation of the Democratic National Committee in their selection."

Roosevelt and Miller concluded that the challenge "fails to meet the criteria for the foregoing reasons" and therefore they are compelled to dismiss it.