A fiercely divided House of Representatives has voted to remove Republican Marjorie Taylor Greene from both her committees after Democrats accused her of spreading hateful and violent conspiracy theories.

Nearly all Republicans voted against the Democratic move on Thursday but none defended her lengthy history of outrageous social media posts.

Yet in a riveting moment, the freshman Republican from a deep-red corner of Georgia took to the House floor on her own behalf. She offered a mixture of back-pedalling and finger-pointing as she wore a dark mask emblazoned with the words “Free Speech”.

The chamber’s near party-line 230-199 vote was the latest instance of conspiracy theories becoming political battlefields, an increasingly familiar occurrence during Donald Trump’s presidency.

He faces a Senate trial next week for his House impeachment for inciting insurrection after a mob he fuelled with his false narrative of a stolen election attacked the Capitol.

Addressing her colleagues, Ms Greene tried to dissociate herself from her “words of the past”.

Contradicting past social media posts, she said she believes the 9/11 attacks and mass school shootings were real and no longer believes QAnon conspiracy theories, which include lies about Democratic-run paedophile rings.

But she did not explicitly apologise for supportive online remarks she has made on other subjects, such as when she mulled about House Speaker Nancy Pelosi being assassinated or the possibility of Jewish-controlled space rays causing wildfires.

And she portrayed herself as the victim of unscrupulous “big media companies”.

News organisations “can take teeny, tiny pieces of words that I’ve said, that you have said, any of us, and can portray us as someone that we’re not”, she said.

She added that “we’re in a real big problem” if the House punished her but tolerated “members that condone riots that have hurt American people” — a clear reference to last summer’s social justice protests that in some instances became violent.

Ms Greene was on the Education and Labour committee and the Budget committee.

Democrats were especially aghast about her assignment to the education panel, considering the past doubt she cast on school shootings in Florida and Connecticut.

“If any of our members threatened the safety of other members, we’d be the first ones to take them off a committee,” Ms Pelosi angrily told reporters.

She said she was “profoundly concerned” about Republican leaders’ acceptance of an “extreme conspiracy theorist”.

House Minority leader Kevin McCarthy said Ms Greene’s past opinions “do not represent the views of my party”.

But without naming the offenders, he said Ms Pelosi had not stripped committee memberships from Democrats who became embroiled in controversy.

Among those he implicated was Ilhan Omar, who made anti-Israel insults for which she later apologised.

“If that’s the new standard,” he said of Democrats’ move against Ms Greene, “we have a long list”.