5 veterans on an advisory board to Sen. Kyrsten Sinema quit in protest, calling her 'one of the principal obstacles to progress'

• Five members of a veterans' advisory council to Sen. Kyrsten Sinema have resigned in protest.
• They cited Sinema's opposition to some of Biden's agenda and her support for the filibuster.

Five members of a veterans' advisory council to Sen. Kyrsten Sinema have resigned in protest over her holding up President Joe Biden's massive social spending package and some of her other positions, The New York Times reported.

In a scathing letter to the senator obtained by The Times and highlighted in an ad from the political arm of progressive veterans' group Common Defense, the members of the group, who informally advise Sinema on military and veterans' issues in Arizona, charged her with "hanging your constituents out to dry."

In a portion of the letter featured in the ad, the resigning members say they "feel they are being used as window dressing" for Sinema's "own image," not to provide guidance.

They particularly criticized on her opposition to plans to lower prescription drug prices, her support for maintaining the current Senate filibuster rules, and her not voting on the measure to create a bipartisan, independent commission to investigate the January 6 insurrection. (Sinema said she missed the vote for a "personal family matter.")

"You have become one of the principal obstacles to progress, answering to big donors rather than your own people," the veteran advisors said in the letter. "We shouldn't have to buy representation from you, and your failure to stand by your people and see their urgent needs is alarming."

The public resignation of about a quarter of Sinema's veterans' advisory board adds to the backlash Sinema is facing in D.C. and at home for her opposition to major components of Democrats' spending package

Sinema has refused to specify which parts of the package she opposes, saying she wants to "respect" the closed-door negotiations with White House officials and Senate Democratic leadership.

The Arizona Senator reportedly doesn't support a measure to allow Medicare to negotiate prescription drug prices and is opposed to some of the proposed tax hikes on wealthy Americans and corporations that would roll back tax cuts passed under former President Donald Trump and provide up to $700 billion in funding for the bill, Insider previously reported.

Some top Democrats in Washington have expressed frustration over Sinema's role in holding up the process as Congress barrels towards the end of the year.

And the Daily Beast has reported that Sinema has iced out many of her longtime friends and political allies and rankled progressive activists in Arizona.

"While it is unfortunate that apparent disagreement on separate policy issues has led to this decision," Sinema said in a statement to The Times about the resigning veterans. "I thank them for their service and will continue working every day to deliver for Arizona's veterans who have sacrificed so much to keep us safe and secure."