Days after reports surfaced about the global consulting firm McKinsey's work advising the Trump administration on immigration policy, calls are growing louder for South Bend, Indiana mayor and 2020 presidential candidate Pete Buttigieg to disclose details about the work he did for the company.

Political observers took notice Thursday evening when the New York Times editorial board joined ethics watchdogs in demanding that Buttigieg release the information, saying his claims that he is bound by a non-disclosure agreement (NDA) create a situation that is "untenable."

"Mr. Buttigieg owes voters a more complete account of his time at the company. Voters seeking an alternative to Mr. Trump should demand that candidates not only reject Mr. Trump's positions, but also his behavior—including his refusal to share information about his health and his business dealings," the editors wrote. "This standard requires Mr. Buttigieg to talk about his time at McKinsey."

"The NDA is about as legitimate an excuse as Donald Trump claiming an IRS audit is the reason he can't release his tax returns to the public. There is no scenario whereby McKinsey would sue Pete Buttigieg, a rising political star and possible president of the United States, for violating a nondisclosure agreement."

—Jeff Hauser, Revolving Door ProjectButtigieg worked for McKinsey from 2007 to 2010 and claims he worked in a junior position. He wrote briefly about his time at the company in his memoir, "Shortest Way Home," acknowledging consulting work he did in Iraq and Afghanistan and in retail and corporate sectors.

The company, denounced by one critic as a "corporate greed machine," has advised authoritarian regimes, including Saudi Arabia's monarchy, state-owned companies in China, and the autocratic government of Turkish President Recep Tayyip Erdogan. In 2017 McKinsey consultants advised President Donald Trump's Customs and Border Protection (CBP) agency on "detention savings opportunities," recommending ways to reduce the amount of food and medical care immigrants were given while being detained by the U.S. government. The proposed cuts made "some career ICE workers uncomfortable" with the effects they would have on immigrants' wellbeing, the New York Times and ProPublica reported.

Although Buttigieg no longer worked for McKinsey when the company advised CBP and ICE, Jeff Hauser of the government watchdog Revolving Door Project told the Huffington Post that Buttigieg must confirm whether his work was guided by the same worldview that led the company to recommend letting asylum-seekers go hungry to save money.

"We have plenty of experience that shows us how seeing the whole world in dollars and cents can be pretty harmful to vulnerable and poor people," Hauser said. "Is that Pete Buttigieg's approach to governance? If he can show he rebelled against that approach, that would be material to people, too."

Hauser was among the critics who scoffed this week at the notion that McKinsey would take legal action against a high-profile presidential candidate who counts McKinsey employees among his top donors:

The NDA is about as legitimate an excuse as Donald Trump claiming an IRS audit is the reason he can't release his tax returns to the public. There is no scenario whereby McKinsey would sue Pete Buttigieg, a rising political star and possible president of the United States, for violating a nondisclosure agreement. The political risk is not that his former employer, a multibillion-dollar corporate entity that promotes fraud across the globe, will be mad at him. It's what he would have to disclose.

On social media, journalist Irin Carmon agreed.

In the past 2-3 years, scores of women and men have broken their NDAs at great personal risk to inform the public interest. And anyway, what are the odds McKinsey goes after Buttigieg for disclosing client names and projects, in this political environment? — Irin Carmon (@irin) December 6, 2019

"Looking afraid of a company that advised cutting food and medical services to immigrant detainees is a great look for a Democratic primary," Carmon added sarcastically.

On Thursday, Sen. Elizabeth Warren (D-Mass.) demanded transparency from her opponent in the Democratic presidential primary, noting that aside from the secrecy surrounding Buttigieg's work for McKinsey, the mayor should "open up the doors" to his private high-dollar fundraisers and let the media and the public know the names of his bundlers—major donors who solicit large contributions from others.

"Those doors shouldn't be closed, and no one should be left to wonder what kind of promises are being made to the people that then pony up big bucks to be in the room," Warren said.

Buttigieg's campaign attempted to turn Warren's comments back on her, with communications advisor Lis Smith calling on the senator to release her tax returns from her time as a corporate lawyer.

But unlike Buttigieg, Slate journalist Jordan Weissman wrote, Warren has a long, public record of fighting powerful corporations on behalf of working people. She has also released a list of clients she worked for in the private sector.

"This whataboutism might be more effective if Warren hadn't gotten into politics by fighting the bankruptcy bill and creating the CFPB," tweeted Weissman.

Citizens for Responsibility and Ethics in Washington said Buttigieg's refusal to release information about his time at McKinsey could soon draw comparisons to President Donald Trump's failure to disclose his tax returns.

"It's a real fear of ours that Democrats and future Republican candidates for president will say, 'Well, Trump got away with it, so we are going to, too,'" CREW communications director Jordan Libowitz told the Huffington Post. "Part of that is not letting Trump get away with it, part of that is holding Democrats to the same standard."