By David Morgan
WASHINGTON (Reuters) - U.S. Senate Republicans were poised on Wednesday to try to up-end Democratic President Joe Biden's COVID-19 vaccine and test mandate for private businesses, in a legislative push that appeared to have enough support from Democrats to succeed.
Republican Senator Mike Braun was expected to appear on the Senate floor to set up a vote for later in the day, under a law that allows Congress to overturn executive orders, an aide said.
The legislation, which is likely to pass the Senate - but was likely to face strong headwinds in the House of Representatives and a likely presidential veto threat - would overturn Biden administration rules ordering larger private businesses to require vaccinations or coronavirus testing for millions of workers.
The measure is not subject to Senate rules that require 60 of the 100 members to agree on most legislation, meaning it could pass with just a 51-vote simple majority. Two Senate Democrats -- Joe Manchin and Jon Tester -- have voiced support for the bill.
If passed, it would face an uphill battle in the Democratic-controlled House. The White House has also warned that Biden could veto the measure.
The initiative, along with a similar Republican effort that failed in the Senate last week after risking a government shutdown, underscores the intense political opposition facing Biden administration efforts to combat COVID-19, at a time when health officials are trying to contain the highly contagious Omicron variant.
On Tuesday, a U.S. judge in Georgia blocked a Biden vaccine mandate aimed at federal contractors.
The United States has the world's highest daily average of new coronavirus infections. COVID-19 infected 49.5 million Americans and killed more than 794,000, according to the Reuters COVID-19 Tracker.
The White House said in a statement on Tuesday that employers would face no burden from the mandate because the vast majority of American adults are fully vaccinated and the rule exempts small businesses.
(Reporting by David Morgan; additional reporting by Trevor Hunnicutt; Editing by Scott Malone and Jonathan Oatis)