Several business groups expressed concern about President Joe Biden’s Covid vaccine mandate on Thursday, arguing that the requirements will burden businesses during the busy holiday season as they rush to meet an implementation deadline that comes shortly after New Year’s day. The mandate, which applies to businesses with 100 or more workers, requires U.S. companies to ensure their employees have gotten vaccinated, or face regular testing, by Jan. 4. However, all unvaccinated workers must start wearing masks indoors a month earlier on Dec. 5, according to the new rules issued by the Occupational Safety and Health Administration, or OSHA, under the Labor Department.OSHA will also conduct on-site workplace compliance inspections, with penalties for violating the rules ranging from $13,653 up to $136,532.The National Retail Federation and the Retail Industry Leaders Association, which requested a 90-day implementation period during meetings with White House officials last month, said the mandate would burden their members during the busy holiday shopping season. “Since the president’s announcement of the vaccine mandate for private industry, the seven-day average number of cases in the United States has plummeted by more than half,” said David French, NRF’s senior vice president for government relations.”Nevertheless, the Biden administration has chosen to declare an ’emergency’ and impose burdensome new requirements on retailers during the crucial holiday shopping season,” French said.The Retail Industry Leaders Association called the implementation period “insufficient” and said the potential fines for noncompliance are “unnecessary and unhelpful,” warning that “it pits government against private employers instead of working with them to create a safe working environment.””While the mandate on private employers technically begins post-holiday, the planning time to design and implement the mandate will fall during the busiest part of the shopping season,” the association said in a statement on Thursday.The National Federation of Independent Business said OSHA’s new mandate makes it “even more difficult and troublesome” for small-business owners to operate in an already challenging environment. “NFIB remains opposed to this rule that restricts the freedom of small business owners to decide how best to operate their own businesses and imposes unwarranted burdens on small businesses that further threaten the small business recovery,” said Karen Harned, executive director of NFIB’s Small Business Legal Center, in a statement Thursday. Senior administration officials said OSHA will help companies come into compliance with the mandate, by providing sample implementation plans, factsheets and other forms of outreach.The Biden administration also pushed back the deadline for federal contractors to comply with a stricter set of vaccine requirements for staff to Jan. 4 from Dec. 8, to match the deadline set for other private companies and health-care providers.Business Roundtable President and CEO Joshua Bolten welcomed the extension for the mandate for federal contractors, while emphasizing that “implementation is a critically important issue” and reiterating calls for the Biden administration to be flexible with companies.He noted difficulties with employee retention, pre-holiday supply chain challenges and “the complexities involved for many companies” that have to comply with both the new federal and private health rules.The U.S. Chamber of Commerce, which dubs itself the world’s largest business organization, in a statement appeared supportive of the “significant adjustments” that OSHA made to the vaccine mandate “that reflect concerns raised by the business community.”The group said it would focus on “helping our members ensure that their employees are vaccinated,” and that it would flag employers’ “operational and implementation issues” to OSHA.The National Association of Manufacturers is worried about “undue cost burdens” as the mandate is implemented. Jay Timmons, president and CEO of the National Association of Manufacturers, called for the Biden administration to remain flexible. “Federal vaccine requirements should be flexible enough to ensure we can achieve those goals, and we appreciate OSHA taking many of our inputs into consideration,” Timmons said. “We are still reviewing the rule, but we will continue to share manufacturers’ perspectives and experiences with the administration to make sure our members aren’t faced with undue cost burdens and other potential disruption,” he said. The United Auto Workers union in a statement flicked at the complexity of enforcing the new Covid-related mandates, saying, “We will review our over 700 employer contracts and see how this rule impacts the current protocols in place at different worksites as well as any impacts on terms of our existing contracts.”Federal contractors subject to the stricter mandate include large airlines like American, Southwest and Delta, which fly U.S. mail and government employees, as well as Boeing, IBM and others.Pilots’ labor unions at American and Southwest had been particularly vocal against the mandate, saying it should be a medical decision for each pilot. The Southwest Airlines Pilots Association had sought to block the implementation of the mandate but a federal judge in Texas last week denied that request and dismissed the union’s lawsuit.Both labor unions cheered the delay for federal contractors. “We are pleased to hear that the Biden administration has heard labor and industry concerns about the deadline occurring before the busy holiday season,” said the Southwest’s pilots’ union president, Casey Murray, in a statement. “While the mandate remains concerning, this new date will surely give SWA a chance to better plan and negotiate with SWAPA regarding protocols surrounding the mandate and how they affect our pilots.”Southwest said it was reviewing the updated guidance but didn’t say whether it would push back the internal deadline for vaccinations.Late last month, some of the nation’s largest unions pushed the Biden administration to expand its vaccine mandate plans to include more employee protections. That group included the AFL-CIO and United Food and Commercial Workers, both of which had argued in a lawsuit against the Biden administration that OSHA’s Covid safety standards were inadequate.UFCW International President Marc Perrone said Thursday that while the new mandate did not go far enough, it nonetheless offered “a critical first step to keep workers safe on the job.””The brutal truth is that this pandemic is far from over,” Perrone said.— CNBC’s Melissa Repko contributed to this report.