Several business groups expressed concern Thursday about President Joe Biden’s Covid vaccine mandate, arguing that the requirements will weigh on companies during the busy Christmas season as they rush to meet an implementation deadline shortly after the New Year.

The mandate, which applies to companies with 100 or more employees, requires U.S. companies to ensure that their employees are vaccinated or regularly tested by January 4th.

However, all unvaccinated workers are required to wear masks indoors a month early on December 5th, according to new rules issued by the Department of Labor’s Occupational Health and Safety Authority (OSHA).

OSHA will also conduct on-site compliance inspections in the workplace, with penalties for violating the rules ranging from $ 13,653 to $ 136,532.

The National Retail Federation and Retail Industry Leaders Association, which called for a 90-day implementation deadline in meetings with White House officials last month, said the mandate would weigh on their members during the busy Christmas shopping season.

“Since the president’s announcement of the vaccine mandate for the private sector, the average seven-day number of cases in the US has fallen by more than half,” said David French, senior vice president of government relations for the NRF.

“Even so, the Biden government has chosen to declare an ’emergency’ and impose burdensome new requirements on retailers during the crucial Christmas shopping season,” said French.

The Retail Industry Leaders Association called the implementation deadline “insufficient” and said the potential fines for non-compliance were “unnecessary and not helpful”.

“While the mandate for private employers technically begins after the holiday, the planning time for the design and implementation of the mandate falls during the busiest time of the shopping season,” the association announced on Thursday.

The National Federation of Independent Business said OSHA’s new mandate made it “even more difficult and arduous” for small business owners to work in an already challenging environment.

“The NFIB continues to oppose this rule, which limits the freedom of small business owners to choose how best to run their own businesses and places unjustified burdens on small businesses that further threaten small business recovery,” said Karen Harned, executive Director of NFIB Small Business Legal Center, in a statement Thursday.

Senior administrators said OSHA will help companies meet the mandate by providing sample implementation plans, fact sheets, and other forms of contact.

The Biden government has also moved the deadline for federal contractors to meet stricter vaccine requirements for staff to January 4, December 8, to meet the deadline for other private businesses and healthcare providers.

The President and CEO of the Business Roundtable, Joshua Bolten, welcomed the extension of the mandate for federal contractors, but stressed that “implementation is an extremely important issue” and again called on the Biden government to be flexible with companies.

He highlighted employee retention difficulties, pre-holiday supply chain challenges, and “the complexities many businesses have” facing both new state and private health regulations.

The US Chamber of Commerce, describing itself as the world’s largest corporate organization, appeared in a statement to support the “significant adjustments” OSHA has made to the vaccine mandate, “reflecting business concerns.”

The group said it would focus on “helping our members make sure their employees are vaccinated,” and they would report employers’ “operational and implementation issues” to OSHA.

The regional association of manufacturers fears “unreasonable cost burdens” in the implementation of the mandate. Jay Timmons, President and CEO of the National Association of Manufacturers, urged the Biden administration to remain flexible.

“Federal vaccine requirements should be flexible enough to ensure we can meet these goals, and we appreciate that OSHA takes many of our contributions into account,” said Timmons.

“We are still reviewing the rule, but will continue to share manufacturers’ perspectives and experiences with the administration to ensure our members are not faced with unreasonable cost burdens and other potential disruptions,” he said.

In a statement, the United Auto Workers union, undermining the complexity of enforcing the new Covid-related mandates, said: “We will review our 700+ employer contracts and see how this rule affects the current protocols in various workplaces as well as all of its implications on the terms of our existing contracts. “

Federal contractors subject to the stricter mandate include major airlines such as American, Southwest, and Delta, which fly U.S. postal and government employees, as well as Boeing, IBM, and others.

The American and Southwest pilots’ unions were particularly opposed to the mandate, stating that it must be a medical decision for every pilot. The Southwest Airlines Pilots Association tried to block the mandate from being carried out, but a federal judge in Texas denied that motion last week, dismissing the union’s lawsuit.

Both unions hailed the delay for federal entrepreneurs. “We are pleased to hear that the Biden administration has heard workers and industry concerns about the deadline before the busy holiday season,” Southwest Pilots Union president Casey Murray said in a statement. “While the mandate remains worrying, this new date will certainly allow SWA to better plan and negotiate with SWAPA about protocols related to the mandate and how it will affect our pilots.”

Southwest said it was reviewing the updated guidelines but didn’t say it would postpone the internal deadline for vaccinations.

Late last month, some of the country’s largest unions urged the Biden government to expand their vaccination mandate plans to include more worker protection. This group included the AFL-CIO and United Food and Commercial Workers, both of whom argued in a lawsuit against the Biden government that OSHA’s Covid safety standards were inadequate.

UFCW International President Marc Perrone said Thursday that while the new mandate does not go far enough, it is “a crucial first step in ensuring worker safety in the workplace.”

“The brutal truth is that this pandemic is far from over,” said Perrone.

– CNBC’s Melissa Repko contributed to this report.