A bid to give parents the right to vet controversial sex education material used in schools was defeated in the House of Lords.

Lady Blatch failed to persuade Peers new laws were needed to protect youngsters from "explicit and unacceptable" material used by Brighton and Hove Council and East Sussex County Council.

She slammed a booklet called Taking Sex Seriously, which gives children as young as 11 details of sadomasochism, multiple partners and partner swapping.

But Lady Blatch's proposals for a parental vetting of sex education were defeated by 180 to 130 in a heated debate last night.

Peers finally supported the scrapping of Section 28, which banned the "promotion" of homosexuality in schools.

After the vote, Lady Blatch said she was "staggered by the aggressive reluctance" of certain peers to give parents the powers she wanted them to have.

She insisted her aim had been to "protect children from the worst form of sex education and to place the power in the hands of parents to know what is going on in schools. There was wilful misinterpretation of my intentions."

Earlier, Lady Blatch had told the Lords: "Very few parents would allow their 11-year-old to take part in a teacher-led discussion on the use of sexual toys, sadism, masochism, dressing up and tying up involving multiple partners in sex and other activities which I cannot bring myself to repeat on the floor of the House.

"Yet there are local authorities that recommend such resources."

Gay rights campaigners hailed the fall of Section 28 as a "triumph for tolerance".

Ben Summerskill, chief executive of gay rights organisation Stonewall, said it was "deliberately framed in order to stigmatise a minority group".

"We're delighted that the House of Lords has demonstrated a willingness to listen to reason at last," he said.

"Stonewall has worked long and hard to have this deeply offensive law overturned."

A spokesman for the Deputy Prime Minister's Office later said: "The Government very much welcomes the House of Lords vote to support repeal of Section 28.

"We have always said this is an unnecessary piece of legislation which is deeply offensive to many people and which stigmatises certain lifestyles."