A new opinion poll indicates a drop in support for a proposed ban on same-sex marriages in California.

Proposition 8 will be put before voters in the state on election day in November.

In July the state attorney general changed the wording of the measure from “amends the California Constitution to provide that only marriage between a man and a woman is valid or recognised in California” to “changes California’s Constitution to eliminate right of same-sex couples to marry.”

Before the change 42% of people likely to vote told a Field Poll they would support the measure, but a recent poll this month found that only 38% were now in favour.

In the July poll 51% opposed Proposition 8. In the recent poll 55% were against it.

Last month Christians, Mormons, Jews, Sikhs and Hindus were asked to join an interfaith alliance hoping to place one million signs in front gardens across the state backing Prop 8.

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

The Court voted 4 to 3 to strike the ban on gay marriage in California, making the state only the second in the US after Massachusetts to allow same-sex couples to marry legally under state law.

Hollywood star Brad Pitt has made a large donation to a campaign fighting an attempt to ban gay marriage in California.

His $100,000 (£54,840) gift to the campaign against Proposition 8 was announced yesterday.

“Because no one has the right to deny another their life even though they disagree with it, because everyone has the right to live the life they so desire if it doesn’t harm another, and because discrimination has no place in America, my vote will be for equality and against Proposition 8,” Mr Pitt said in a statement.