Sean Penn is refusing to complete his final weeks of production on his U.S. TV series Gaslit until every cast and crew member has been vaccinated against Covid-19.

The star isn't satisfied with Gaslit production bosses' assurances that everyone in the show's Zone A - reserved only for actors and those workers needing to be in contact with them - will be jabbed.

His decision was first reported by Deadline and the actor's representatives confirmed the story to Variety.

Oscar winner Penn, who reportedly only has two weeks left of production, has offered to facilitate the mandatory-for-all vaccination drive, free of charge, through his non-profit organisation Community Organized Relief Effort (CORE), which helped California's coronavirus testing and vaccine rollout.

The state's Covid-19 case numbers are soaring again, due to the rapid spread of the Delta virus variant, prompting Los Angeles County health leaders to reintroduce a mandate requiring compulsory mask-wearing indoors last week.

On Monday, company officials at NBCUniversal released a statement announcing that producers working with the American media giant have "the option to implement mandatory vaccination policies for casts and crew in Zone A on a production-by-production basis".

And on Wednesday, according to Deadline, they emailed everyone working on Gaslit, informing them of a free vaccination clinic offering "several vaccine choices", with second doses to be administered 21 days later if necessary. The missive also asked production members to bring proof that they have been jabbed when they next report to work on the set.

Penn plays disgraced former U.S. President Richard Nixon's Attorney General, John Mitchell, in the upcoming series about the Watergate political scandal. Julia Roberts is playing his wife Martha.