US President Donald Trump's choice for secretary of labour, Andrew Puzder, has prompted anger among workers' rights campaigners and labour groups across the United States.

Puzder's confirmation hearing is scheduled for tomorrow.

Adam Shah, a senior policy analyst at the Jobs With Justice union rights organisation based in Washington, DC, described Puzder as "the fox guarding the henhouse", and said that his nomination was an indicator that Trump's general approach to labour organisations will be "unfriendly to workers".

Puzder is chief executive of CKE Restaurants, which includes the popular fast-food chains Hardee's and Carl's Jr and has been accused of numerous violations of workers' rights and discriminatory workplace practices.

"Puzder has a record not only of opposing expansions to labour rights - such as the minimum wage and making overtime rules more enforceable - but he is also a serial violator of labour laws," Shah told Al Jazeera.

In a letter published online, current and former labour department employees called on the Senate Committee on Health, Education, Labor and Pensions (HELP) to oppose Puzder's nomination, citing allegations of anti-worker business practices and sexism.

"In the anti-discrimination context, Hardee's and Carl's Jr have had more federal discrimination lawsuits brought against them since 2000, when Mr Puzder took over, than any other major hamburger chain," the letter reads.

"The Secretary of Labour should be a leader in opposing employment discrimination, not the head of a company that is a leading defendant in discrimination lawsuits."

Puzder recently admitted to employing an undocumented immigrant as a housekeeper for several years and never paying legally mandated taxes on her wages until shortly before his nomination.

After these revelations surfaced, more than 130 organisations - labour groups and workers' rights advocates, among others - released a statement last week demanding Puzder withdraw his nomination for labour secretary.

"If he cannot be trusted to follow even one of the most basic laws of employment in his own home, there is no way we can expect him to enforce the crucial laws the Department of Labor oversees on behalf of working people," the statement reads.

Puzder's confirmation hearing has been delayed four times. With at least four Republican senators reportedly withholding support, his confirmation is expected to be a struggle.

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Minimum wage struggle

George Thompson, Puzder's spokesman, rejected criticisms of the nominee as anti-workers' rights.

"Andy Puzder has an excellent record for protecting workers and creating jobs - despite the 'fake news' being spewed by his critics," he told Al Jazeera by email, arguing that Puzder is a "proven jobs creator".

Thompson added: "Andy Puzder supports rational increases in the minimum wage and he is proud that people at his company do not make minimum wage for very long, as good workers move up quickly and earn promotions."

Yet labour advocates and analysts point out that Puzder has repeatedly opposed efforts to increase the federal minimum wage, making him an opponent of many unions and campaigns to raise the minimum wage.

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Puzder has also been critical of expansions to paid sick leave and overtime pay, as well as the Affordable Care Act, the federal statute on healthcare enacted in 2010.

The current federal minimum wage is $7.25 an hour, although individual states within the US can set their minimum wage regulations higher.

Fight for $15, a national campaign to raise the minimum wage, has protested against Puzder's nomination. On Monday, the campaign held protests attended by thousands of workers in 24 cities across the country.

In St Louis, Missouri, an estimated 500 people demonstrated against Puzder's nomination outside Hardee's former corporate headquarters, while hundreds more assembled at CKE Restaurants' corporate offices in Anaheim, California.

"The protests were huge, they were militant," said Kendall Fells, the national organising director of the Fight for $15. "People are upset and outraged that someone like Andy Puzder would even be nominated."

Under Puzder's oversight, CKE Restaurants has also been accused of wage theft, sexual discrimination and retaliation and intimidation against workers who attempted to organise unions.

Referring to Puzder's opposition to raising the minimum wage, Fells said: "There is no city in the country in any state where you can survive on less than $15 an hour ... you don't survive off of $7.25 an hour. You live in homeless shelters, you sleep in your car and you go into debt; but you don't survive."

He added: "Puzder is clearly someone who has stood in the way and been an obstacle to the 64 million workers in this country who have been trying to pull themselves out of poverty."

Violations

While the labour department is in many ways less consequential for workers than federal departments, Puzder could still "do much more harm to workers and unions", according to Stephanie Luce, a professor of labour studies at City University of New York.

"Everything we've seen from him - including public statements where he says he does not support minimum wages or laws requiring mandatory break - to the functioning of his companies, suggests he will be looking to restrict workers' rights," Luce told Al Jazeera.

"The Department of Labour could cut back inspections, cut back data collection, redirect resources and eliminate important programmes."

The Century Foundation, a progressive think-tank, analysed and mapped the available data on CKE Restaurants' Occupational Safety and Health Administration (OSHA) violations since 2000 and investigations by the Wage and Hour Division (WHD) since 2004.

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The map shows that 52 percent of 166 WHD and OSHA investigations together found at least one violation, while while 51 percent of OSHA investigations found a total of 91 violations affecting at least 576 employees. Between 2004 and 2016, CKE Restaurants had to pay $145,310 in back wages to 877 employees for WHD violations.

The Century Foundation concluded: "What is clear is that CKE is a representative of the kind of corner-cutting that hurts workers."

Two-thirds of female fast food workers at restaurants operated by Puzder reported that they endured sexual harassment, according to a survey conducted by Restaurant Opportunities Centre United.

The growing anger over Puzder's nomination comes amid a flurry of measures targeting workers and labour unions, which hit an all-time low in 2016, with only 10.7 percent of the national workforce carrying union membership. Among private sector workers, only 6.4 percent are union members.

Trump signed an executive order to begin removing restrictions on Wall Street, effectively reversing a law that overhauled the financial industry in 2010 after the economic crisis that affected the US and much of the world.

Earlier this month, Republicans introduced a national right-to-work bill in Congress. If passed, that bill will prohibit requiring workers to support a union.

Citing Trump's early policies and noting that his "administration is made up of billionaires and millionaires", Adam Shah, of Jobs With Justice, concluded: "The department of labour is a crucial branch that ... should be representing working people nonetheless."

Follow Patrick Strickland on Twitter: @P_Strickland_