Fewer than half of California voters back billionaire tax: Poll

California's state ballot measure proposing a 5 percent tax on the state's 200 billionaires' net worth is losing support, according to a new poll released Monday.

The University of California, Berkeley Citrin Center for Public Opinion Research-POLITICO poll found that 45 percent of registered California voters support the ballot measure Proposition 40, known as the Billionaire Tax Act. The measure faces opposition from 43 percent of voters, and 12 percent say they are undecided.