The potential VP is set to be announced today according to US media outlets
Democratic presidential candidate Hillary Clinton will pick Senator Tim Kaine as her running mate, US media report.
Democrats close to the former Secretary of State said she was expected to make the announcement in an email to supporters while campaigning in Florida on Friday afternoon.
Liberals had hoped she would pick a vice presidential running mate with a tougher stance on Wall Street, such as Massachusetts Senator Elizabeth Warren.
But Mr Kaine could give Mrs Clinton a boost in Virginia, a pivotal battleground state that could pave her path to the White House.
Her campaign reportedly hopes the welder's son could also help her woo white male voters, a demographic she has consistently struggled to win over.
Mr Kaine, 58, is a Harvard-trained lawyer, who was elected mayor of Richmond, Virginia, and the state's governor, before joining the Senate.
Other possible Democratic VP finalists were said to include Agriculture Secretary Tom Vilsack, Labor Secretary Tom Perez, New Jersey Senator Cory Booker and Ohio Senator Sherrod Brown.
Mrs Clinton will be anointed as the party's official presidential candidate along with her running mate at next week's Democratic National Convention in Philadelphia.
Her announcement will be timed to snatch attention away from newly minted Republican nominee Donald Trump, hours after he closed his convention with a fiery speech.