NBC NEWS - Andy Puzder, President Donald Trump's nominee for labor secretary, is expected to withdraw his nomination on Wednesday amid growing questions about his business record and scrutiny from senators on both sides of the aisle, a senior administration official confirmed to NBC News.

A senior GOP source on Capitol Hill called Puzder's nomination "dead."

The head of CKE Restaurants, which owns Hardee's and Carl's Jr., came under harsh criticism from Democrats and liberal groups for his opposition to raising the minimum wage, past controversial comments, and the racy ads his properties have used to promote the fast-food chains.

But it was Republicans who toppled Puzder. On the day before his confirmation hearing was expected to take place, more and more Republicans withheld support, saying that they'd like to wait until they hear from him in the hearing.

Puzder is the first of Trump's cabinet nominees to withdraw his nomination.

"This is a nominee, who probably is best suited, in terms of experience, knowing what to do at the deptartment of labor and how to get the yoke of federal regulations off of everybody. But obviously we'll bring up one or two concerns," said Sen. Pat Roberts, R-Kansas, a member of the Health, Education, Labor and Pensions Committee with oversight of his confirmation. "I'd like to support him, but I want to go through the hearing."

Roberts was just one of the half dozen Republicans on the committee, which hosts twelve members of the GOP, to express reservations.

Sen. Johnny Isakson, R-Georgia, said, "I'm going to the hearing tomorrow and I'll make my decision then."

Some conservatives have also taken issue with Puzder's immigration stance, saying it is at odds with Trump. His family also employed an undocumented worker as a housekeeper, though Puzder said he was unaware she was in the country illegally.

Personal issues also complicated the restaurant executives nomination. Puzder went through a messy divorce and his ex-wife made allegations of domestic abuse that were later recanted.

A 27-year-old video of the Oprah Winfrey Show surfaced his ex-wife making domestic abuse allegations. The Oprah Winfrey Network released the video and the Senate HELP committee and Chairman Lamar Alexander, R-Tennessee, provided several viewings of the show for committee members.

Republican concerns coupled with Democrats unified opposition doomed Puzder's confirmation.

Democrats pointed to the high number of complaints by women employees who work for his company. They also took issue with his opposition to minimum wage, overtime protections and paid sick days.

Puzder has been unenthusiastic about the grueling process of revealing personal and financial information to the Senate for confirmation. His record has been scoured and his workplace practices have been highly criticized.

His confirmation hearing was postponed four times because he failed to turn in the required paperwork.

Democrats will count Puzder's defeat as a win.

The bar to defeat a nominee has dramatically risen because of rule changes in 2013 that allow cabinet nominees to pass the Senate with the support of 51 senators instead of 60, meaning it takes bipartisan opposition to defeat a nominee.

Sen. Bernie Sanders, I-Vermont, said he's "glad" Puzder is withdrawing his nomination.

"The simple truth is that given his relationship to employees at the companies he runs, he was not fit to lead a department responsible for defending workers' rights," Sanders said.