Billionaire Marc Benioff celebrates after San Francisco votes for new tax that will take millions from big tech firms to solve the city's homelessness crisis

Kimberly White / Stringer

Salesforce CEO Marc Benioff.

• Proposition C, a measure which will tax San Francisco's largest companies in order to combat homelessness, passed on Tuesday.
• Salesforce CEO Marc Benioff has been a vocal proponent of Prop C and hailed the victory in a tweet.
• Prop C would target Salesforce, which Benioff has estimated will pay between $10 million and $11 million a year.

Marc Benioff has tweeted jubilantly following the success of Proposition C.

The tax scheme was voted through on Tuesday during the US midterms. It will tax big San Francisco companies whose gross annual receipts total $50 million to raise money to combat the city's homelessness crisis.

Benioff, the billionaire Salesforce CEO, has been a vocal proponent of Prop C, which has divided tech CEOs in recent weeks, with the debate spilling over on to social media.

In October, he publically argued with Twitter CEO Jack Dorsey, who thinks there is a better way to tackle homelessness, and later said: "You're either for the homeless and for the kids and for the hospitals, or you're for yourself." He also locked horns with Zynga's chairman and cofounder Mark Pincus.

Read more: Salesforce CEO Marc Benioff on his Twitter beef with Jack Dorsey: You're either 'for the homeless' or 'you're for yourself'

On Tuesday, Prop C, which has been predicted to raise between $250 million and $300 million beginning in 2019, passed with 60% of the vote in San Francisco, and Benioff celebrated on Twitter.

Benioff's company Salesforce would be among the firms targeted by the tax, and Benioff has said it would have to pay between $10 million and $11 million a year into the scheme.

Critics of the tax, including San Francisco Mayor London Breed, said that Prop C was ill-built to fully address the city's homelessness crisis. The scheme is also known as the "Our City, Our Home" initiative.