U.S. Congressman Eric Swalwell has dropped out of the California governor race following growing pressure over sexual misconduct allegations.

The Democrat has been accused by four women of misconduct ranging from sexual harassment to rape. He has denied the claims and vowed to defend himself with facts.

Top allies had called on him to exit the gubernatorial race, in which he was projected as one of the frontrunners among Democratic candidates.

His departure comes at a pivotal moment in the wide-open primary race, just weeks before voters receive postal ballots ahead of the 2 June election to replace outgoing Governor Gavin Newsom and to lead the nation's most populous state.

Swalwell said in a post on X: I am suspending my campaign for governor. To my family, staff, friends and supporters, I am deeply sorry for mistakes in judgment I've made in my past. I will fight the serious, false allegations that have been made - but that's my fight, not a campaign's.

Swalwell's decision to suspend his campaign comes two days after the first allegations emerged in the San Francisco Chronicle. A former staff member accused him of making inappropriate comments and soliciting her for sex shortly after she was hired.

The woman stated that she woke up naked in Swalwell's hotel room one night with little recollection of the preceding events. She corroborated her story with texts sent to friends and her former boyfriend, who encouraged her to report the incident.

Within hours of the accusations surfacing, Swalwell lost the backing of prominent supporters, including Senator Adam Schiff and House Democratic Leader Hakeem Jeffries.

His legal team had sent cease-and-desist letters to two of the accusers before he publicly denied the allegations. For nearly 20 years, I have served the public - as a prosecutor and a congressman and have always protected women. I will defend myself with the facts and where necessary bring legal action, he stated.

At least 10 candidates are expected to be on the ballot in the primary, which will include both Democrats and Republicans. The top two vote-getters in the primary will proceed to the general election regardless of party affiliation.