Big money is behind Lt. Gov. Gavin Newsom’s gun control referendum, Proposition 63, which appears on California’s general election ballot this November.

Supporters have raised almost $4 million for what is billed as “Newsom Ballot Measure Committee; Safety for All”  — almost nine times the contributions made against it.

Meanwhile, only about $426,000 has been raised in opposition. California’s Secretary of State (SOS) reports that gun control supporters have spent almost $3.72 million thus far — almost all of the contributions received — while the opposition appears to have gone into debt spending $498,952, more than the contributions received.

Prop. 63 would, according to the SOS:

Prohibits possession of large-capacity ammunition magazines, and requires their disposal by sale to dealer, destruction, or removal from state. Requires most individuals to pass background check and obtain Department of Justice authorization to purchase ammunition. Requires most ammunition sales be made through licensed ammunition vendors and reported to Department of Justice. Requires lost or stolen firearms and ammunition be reported to law enforcement. Prohibits persons convicted of stealing a firearm from possessing firearms. Establishes new procedures for enforcing laws prohibiting firearm possession by felons and violent criminals. Requires Department of Justice to provide information about prohibited persons to federal National Instant Criminal Background Check System

Newsom’s 2018 gubernatorial election campaign, combined with his 2014 campaign re-election committees, have donated over $730,000 in support of Prop 63, according to the SOS.

The California Democratic Party also donated over $1.1 million to push Newsom’s gun control measure. The Los Angeles Times identified $400,000 contributor Sean Parker as the former Facebook president.

Also among those contributing in support of the gun control ballot measure are 20th Century Fox writer Ian Brennan; 20th Century Fox writer/producer Steven Levitan; Game of Thrones Executive Producer David Benioff; Benioff’s wife and actress Amanda Peet; Hollywood producer and writer Naomi Scott; and major donor to Hillary Clinton Susie Tompkins Buell.

The California Rifle and Pistol Association spearheaded one of two committees opposing the gun control measure, the Coalition for Civil Liberties. The second committee is the Firearms Policy Coalition Second Amendment Defense Committee, which received significant contributions from Firearms Policy Coalition, Michael Borland and Caryn Borland.

Follow Michelle Moons on Twitter @MichelleDiana