A California ‘family’ group is seeking a voter referendum on a new state law requiring schools to teach pupils about gay history.

The Capitol Resource Institute, a socially conservative group, has long campaigned against the legislation, which was signed into law last week.

According to the Sacramento Bee, the group’s legislative director Paulo Sibaja has filed a request for a title and summary with the attorney general’s office.

Mr Sibaja said more information about the effort would be given at a press conference on Wednesday.

To win a vote on the legislation, known as the Fair Education Act, the group will have to collect 433,971 signatures.

Democrat Senator Mark Leno, who introduced the bill to the Senate, called the group “extremist” and added: “I think it will be a challenge for them to get the signatures.”

The law makes the state the first in the US to ensure that all children learn about figures such as San Francisco gay rights campaigner Harvey Milk.

It also bans “discriminatory” teaching material.

California law already requires schools to highlight the contributions of women, African-Americans, Mexican Americans and entrepreneurs, among others.