Buttigieg, emphasizing transparency on campaign trail, to open fundraisers, release McKinsey clients

With an increased emphasis on transparency on the campaign trail, Pete Buttigieg has been at the center of attacks regarding two main issues: His high-dollar private fundraising and the secrecy behind his work at the consulting firm McKinsey that's shielded by a non-disclosure agreement. Now, his 2020 competitors will have to look elsewhere to go after the presidential hopeful.

After a public call to his former employer to release information about his time at McKinsey, the company decided on Monday to allow Buttigieg to reveal the clients he worked for from 2007 to 2010.

“After receiving permission from the relevant clients, we have informed Mayor Buttigieg that he may disclose the identity of the clients he served,” a spokesperson for McKinsey said in a statement, adding that the firm takes its commitments to clients seriously, including protecting their confidence, but “recognize the unique circumstances presented by a presidential campaign.”

Buttigieg released a summary of his three years at the firm last Friday. He said that in 2007, he served a nonprofit health insurance provider for three months in Michigan, and in 2008 he worked in the Toronto area analyzing prices for a grocery and retail chain. In 2008 and 2009, he worked mostly in Connecticut on research to fight climate change by improving energy efficiency, and in 2009 he worked in California for an environmental nonprofit. That same year, he also worked in Washington, with trips to Iraq and Afghanistan, for the U.S. government. His final project for McKinsey was from 2009 to 2010, analyzing logistics for a shipping provider.

In its statement, the consulting firm confirmed that the clients Buttigieg described “are all of the clients he served during his time at McKinsey.” Buttigieg’s senior communications adviser Lis Smith tweeted that the campaign would be releasing a list of clients soon.

Following a forum in Waterloo, Iowa, on Friday night, Buttigieg fielded a barrage of questions from reporters who asked if he would break his NDA or how long he would wait for McKinsey to respond to his plea. Earlier that day, the mayor told ABC News’ Whit Johnson, "I don't think that McKinsey should force me to choose between keeping my word in a legal document that I signed in good faith and the need for the American people to know."

A few hours before McKinsey’s decision, Buttigieg’s campaign also put an end to a line of attack from Sen. Elizabeth Warren, announcing that future private fundraisers will be open to press beginning on Dec. 10.

“In a continued commitment to transparency, we are announcing today that our campaign will open fundraisers to reporters, and will release the names of people raising money for our campaign,” Buttigieg campaign manager Mike Schmuhl said in a statement Monday. “Fundraising events with Pete will be open to press beginning tomorrow, and a list of people raising money for the campaign will be released within the week."

While campaigning in Iowa over the weekend, Buttigieg was repeatedly asked by reporters about the lag in making a decision. He said that his team was working through options to open the high-dollar events.

“Just want to make sure we do it in the, you know, if we approach this that we do in the right," he said.

Buttigieg has fended off repeated attacks from Warren as she continued to call him out by name, asking him to be more transparent about his work at the consulting firm.

At a town hall in Las Vegas on Monday night, Warren said she was "glad" to see these changes from Buttigieg, but Democrats need a candidate who can "most aggressively make the comparison" between the Trump administration and how the president raises money.

"That’s why I’ve based my campaign from the very beginning on not selling access to my time. Not giving special titles to bundlers and never having closed door fundraisers," Warren said.

Buttigieg used to release the name of his bundlers early on in his presidential campaign but eventually stopped disclosing that information.

In response to the attacks from Warren, Buttigieg would strike back with a call for the Massachusetts senator to release tax returns from her years as a corporate lawyer -- something Warren says she will not do.

“I certainly think it would be a good idea for her to release tax returns as I have, covering your entire career and in the private sector. I think that's one way to show your transparency. And I believe in transparency again and being as - as open as I can about my story, and what I've proposed today,” the South Bend, Indiana, mayor said.

Warren did however disclose documents on Sunday night, showing that she received nearly $2 million from her private legal work over three decades.

Schmuhl says the Buttigieg campaign “strives to be the most transparent in the field,” pointing to examples of their three open press bus tours in Iowa and New Hampshire, where the mayor was on the record with reporters aboard the bus as it traveled to events, and the release of 12 years of his tax returns that cover all of the 37-year-old’s professional life.

“No other candidate for president has released the entirety of their tax returns since their education concluded. No other current candidate for president has released the names of people raising money for their campaign. There are important differences in this race among Democratic candidates, from creating a choice of affordable health care choices for all to removing cost as a barrier to college for those who need it, but transparency shouldn't be one of them,” Schmuhl said.

ABC News' Ali Dukakis, Sasha Pezenik and Cheyenne Haslett contributed to this report.