A ballot proposition that would remove the right of same-sex couples to get married in California appears to be gaining support.

Less than one month before Proposition 8 goes to the voters, a new poll of 670 people commissioned by CBS in San Francisco found that 47% are going to vote for the ban with 42% likely to vote against.

Polling from 11 days ago showed a five point lead for opponents of the measure.

Pollsters SurveyUSA, said:

“Polling on ballot measures in general is an inexact science, and polling on homosexuality in general is a tricky business. So, not too much should be made of the five points that separates ‘yes’ and ‘no’ today.”

Hollywood stars Brad Pitt, Ellen Degeneres and Steven Spielberg have all given public support to campaigns to overturn Prop 8, an initiative measure on the 2008 California General Election ballot in November.

It would amend the state Constitution to “eliminate right of same-sex couples to marry.”

In May the California Supreme Court overturned a ban on same-sex marriages in the state.

More than 11,000 gay and lesbian couples have tied the knot since the court ruling.