Controversial US congresswoman Marjorie Taylor Greene doubled down Tuesday on equating mask mandates with Nazis forcing Jews to wear yellow stars in war-era Germany, earning a stern rebuke from Republican leadership.

Greene, a freshman Republican from Georgia, tweeted about a business making its employees who are fully vaccinated against the coronavirus wear a vaccination logo on their name badge.

"Vaccinated employees get a vaccination logo just like the Nazi's forced Jewish people to wear a gold star," Greene wrote.

"Vaccine passports & mask mandates create discrimination against unvaxxed people who trust their immune systems to a virus that is 99% survivable."

Greene is a fierce defender of former president Donald Trump and promoter of his baseless claim that Democrats stole the 2020 presidential election.

Her five months in Congress have been repeatedly marked by controversy and rising frustration within her party over her extreme remarks.

But her recent comments linking mask rules to the Holocaust outraged some in her party, including House Minority Leader Kevin McCarthy who denounced her comments -- but also accused Democrats of anti-Semitism.

"Marjorie is wrong, and her intentional decision to compare the horrors of the Holocaust with wearing masks is appalling," McCarthy said in a statement.

US Representative Marjorie Taylor Greene (R-GA) is being criticized for comparing mask mandates to Nazis forcing Jews to wear yellow stars
US Representative Marjorie Taylor Greene (R-GA) is being criticized for comparing mask mandates to Nazis forcing Jews to wear yellow stars GETTY IMAGES / Kevin Dietsch

"Let me be clear: the House Republican Conference condemns this language," he added.

With increased violence against Jews in the United States in recent weeks, "anti-Semitism is on the rise in the Democrat Party and is completely ignored by Speaker Nancy Pelosi," McCarthy said.

"Americans must stand together to defeat anti-Semitism and any attempt to diminish the history of the Holocaust."

The controversy began Sunday when Greene, speaking to a conservative podcast, compared Pelosi's decision to maintain mask rules for lawmakers on the House floor to Nazi actions against Jews.

"You know, we can look back at a time in history where people were told to wear a gold star, and they were definitely treated like second class citizens, so much so that they were put in trains and taken to gas chambers in Nazi Germany," Greene said.

"This is exactly the type of abuse that Nancy Pelosi is talking about."

Greene, who insisted she said nothing wrong, received fierce criticism from both sides of the political aisle, with fellow House Republican Liz Cheney calling the comments "evil lunacy."

Several Democrats have said Greene is unfit to serve in Congress.