Sens. Mark UdallMark UdallGorsuch's critics, running out of arguments, falsely scream 'sexist' Election autopsy: Latinos favored Clinton more than exit polls showed Live coverage: Tillerson's hearing for State MORE (Colo.) and John Walsh (Mont.) on Wednesday became the first Democratic senators to call for Veterans Affairs Secretary Eric ShinsekiEric ShinsekiShulkin confirmed to lead Dept. of Veterans Affairs Dems to Trump: Exclude VA from hiring freeze Dems, GOP battle over pace of Trump confirmations MORE to resign.
Republican calls for Shinseki to quit also grew after the VA's Office of Inspector General released an interim report finding systemic problems at VA facilities where veterans have waited for treatment.
Udall called for the resignation in a message on Twitter after the release of the report.
Udall faces a tough reelection challenge this year from Rep. Cory Gardner (R-Colo.), who had previously called for Shinseki to resign.
“The Inspector General’s report confirms the worst of the allegations against the VA and its failure to deliver timely care to veterans. It is time for President Obama to remove Secretary Shinseki from office," Walsh said.
“Accountability lies with President Obama, Secretary Shinseki, the VA, and also with Congress, which has the obligation to fully fund the costs of war. Congress must provide the resources that will eliminate the backlog and improve the quality of care available to men and women who have served." Walsh concluded.
He also faces a difficult election race, where he is the underdog against Rep. Steve Daines (R-Mont.).
Rep. Scott Peters (D-Calif.) later on Wednesday became the third House Democrat to call for Shinseki to resign. He also faces a tough race in a San Diego district with a heavy military presence against openly gay Republican candidate Carl DeMaio.
House Armed Services Committee Chairman Buck McKeon (R-Calif.), who previously had backed Shinseki, released a statement Wednesday saying it would be best if he stepped down.
“General Shinseki has given his life to serving this country and for that, we are in his debt," his statement said. "However, the problems at the Department of Veterans Affairs have grown beyond what this nation can bear. I believe America’s veterans would be best served with a fresh set of eyes on the VA system. Only new innovations and aggressive reform can get the problems at the VA under control.
"It would be best if General Shinseki stepped down as Secretary, both as an example for other VA leaders and to lay the groundwork for new leadership to meet with success," McKeon concluded.
Sen. John McCain (R-Ariz.) earlier called for Shinseki's resignation.
This story was updated at 4:40 p.m.