Tory MPs will be given a free vote on an amendment to the Local Government Bill seeking reform of Section 28.

The Conservatives have unveiled an alternative to the controversial legislation which outlaws the "promotion" of homosexuality. The amendment, supported by the Tory frontbench, will seek to avoid damaging Conservative splits on the issue by giving the force of law to existing government guidelines on sex and relationship education. Rules which prohibit the stigmatising of any particular sexual orientation but also highlight the importance of marriage.

David Davis, the shadow deputy prime minister, said: "Our number one priority is to offer children genuine protection and to strengthen the rights of parents when it comes to the way children are taught about sex in our schools."