The policy reversal marks a victory for the conservative allies of US President Donald Trump, who have long accused tech platforms and professional fact-checkers of a liberal bias and of using anti-misinformation policies as a pretext for censorship.

"Reflecting the company's commitment to free expression, YouTube will provide an opportunity for all creators to rejoin the platform if the company terminated their channels for repeated violations of Covid-19 and elections integrity policies that are no longer in effect," Alphabet's legal counsel said in the five-page letter to Jim Jordan, the Republican chair of the House Judiciary Committee.

"YouTube values conservative voices on its platform and recognizes that these creators have extensive reach and play an important role in civic discourse."

The full impact of the policy reversal was yet to be determined, and it was not immediately clear which creators would be reinstated and when.

In recent years, figures such as FBI Deputy Director Dan Bongino, White House counterterrorism chief Sebastian Gorka and podcast host Steve Bannon were among those previously banned from the platform, according to US media.

Alphabet accused former president Joe Biden's administration of pressuring the company to impose the bans.

"Senior Biden Administration officials, including White House officials, conducted repeated and sustained outreach to Alphabet and pressed the company regarding certain user-generated content related to the COVID-19 pandemic that did not violate its policies," the letter said.

"While the company continued to develop and enforce its policies independently, Biden administration officials continued to press the Company to remove non-violative user-generated content," it added.

- Policy rollback -

After Biden took office in 2021, his administration urged platforms to purge what it identified as harmful misinformation -- including content that encouraged people to inject bleach and other disinfectants to cure Covid-19, a suggestion once echoed by Trump.

Jordan, who has spent years probing what Republicans have blasted as a coordinated effort by Biden's administration to suppress conservative voices online, celebrated Alphabet's announcement as a "victory in the fight against censorship" and a "massive win" for the American people.

"To make amends to the American people, and because of our work, YouTube is rolling back its censorship policies on political speech, including topics such as Covid and elections," Jordan wrote on X.

"No more telling Americans what to believe and not believe," he added.

Alphabet's letter stressed that "YouTube has not and will not empower fact-checkers to take action on or label content across the company's services."

Instead, it allows users to add notes of context to user content, adopting a community-driven approach to combating online misinformation that was popularized by Elon Musk's platform, X.

The decision to reinstate previously banned users also mirrors Musk's move to welcome back prominent purveyors of misinformation on Twitter, which he rebranded as X after acquiring it in 2022.