If approved, Prop. 6 would rescind the gas tax and vehicle fees enacted by the legislature last year, with a constitutional amendment requiring voter approval for any future increases in gas tax and vehicle fees.
According to the website gastaxrepeal.org, registered voters who purchase gas at 13 participating gas stations between 8 a.m. and 10 a.m. Monday will be eligible to enter a drawing for the free $50 cards.
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Volunteers at the stations, five of which are in Southern California, will be on hand to help drivers enter the drawing. Entrants must agree to provide their information to a Yes on Prop. 6 contest database and receive emails from Reform California, the organization said.
A maximum of 1,000 gas cards will be given away.
A list of the participating Southern California gas stations is below.