WASHINGTON -- Rattled by bitter fights over President Donald Trump's Cabinet picks, Republicans and their allies have launched a fresh campaign to defend fast food executive Andrew Puzder's nomination to lead the Labor Department.

From a social media push, including the Twitter hashtag .confirmpuzder, to old-fashioned letter-writing to senators, the CEO's supporters are pushing back against months of Democratic and labour-led efforts to cast him as favouring business interests over those of U.S. workers.

"Some are asking if @AndyPuzder is qualified for #LaborSec. The answer: let us count the ways. #ConfirmPuzder," the National Restaurant Association tweeted Friday. The lawyer and CEO of CKE Restaurants Inc. "knows how to create jobs, because that's what he has done for the last two decades," it said.

In the testy aftermath of Trump's November election, the fight over his Cabinet nominations has led to marathon Senate sessions and contentious confirmation hearings. In Puzder's case, the increasingly personal debate highlights the push-pull between business and labour issues and raises questions about Trump's stated commitment to American workers who drove his November victory.

Haunting Puzder's backers ahead of his Feb. 16 hearing is Education Secretary Betsy DeVos' bruising journey to confirmation this week, barely. On the same day Vice-President Mike Pence broke the tie vote to confirm DeVos, Senate Majority Leader Mitch McConnell pivoted to the most muscular defence of Puzder's nomination so far, vowing to stick with him despite Puzder's acknowledgement of having employed a housekeeper not authorized to work in the U.S.

Puzder fired the worker but did not pay related taxes until after Trump nominated him Dec. 9. Several GOP members of the Senate committee that will handle his confirmation hearing Feb. 16 say they are concerned by the housekeeper issue. Employing people not authorized to work in the United States has sunk Cabinet nominations by previous presidents.

There's no evidence any Senate Republican will vote against Puzder's confirmation.

Puzder's opponents had long laid the groundwork for their case that workers at Puzder's fast food business, including Hardee's and Carl's Jr., were treated shabbily. They argue that the nominee opposes worker-friendly policies -- such as a big minimum wage hike and an overtime rule that expands the number of eligible people. And they say that despite Puzder's plan to divest from his financial holdings if confirmed, he favours business interests over worker protections enforced by the Labor Department. Their Twitter rallying cry against Puzder: .antilaborsecretary.

On Thursday, Senate Democratic Leader Chuck Schumer called on Trump and Puzder to withdraw the nomination, saying the pair's business records and Puzder's housekeeper issue fly in the face of the president's vow to advocate for workers.

Now, Puzder's backers are doubling down as the nominee himself rehearses for his confirmation hearing. Notably, they're generally not challenging the point that Puzder's business background aligns him with conservative economic views. The most common argument they make is a familiar one to Republicans: that Puzder would help create better-paying jobs by rolling back government rules that are burdensome to businesses.

"Mr. Puzder stands ready to promote and enact pro-growth policies that will benefit working Americans across the board," members of the International Franchise Association wrote in a letter it's expected to deliver Monday to the Senate. The letter says Puzder will "promote regulatory responsibility within the highest ranks of our government to ensure the lasting and prosperous impact of our nation's labour force."

The U.S. Chamber of Commerce urged the Senate and the Senate Committee on Health, Education, Labor and Pensions to confirm Puzder in part because, it said, he would be "the first CEO of a company to go directly to serving as secretary of labour."

"This means he will know better than any other secretary the impact that the department's actions have on companies and the economy," the Chamber's Neil L. Bradly wrote in a letter delivered Thursday night to Republican Chairman Lamar Alexander of Tennessee and ranking Democratic Sen. Patty Murray of Washington.

Puzder's opponents were filling senators' mailboxes too, as the fight raged across social media and advocates for a $15 minimum wage prepared to protest his nomination on Monday.

"It is hard to imagine a worse and more insulting candidate to head a federal agency whose primary role is to advance the welfare of working people," the National Nurses United wrote Friday to members of the committee.