Christine Stewart: "Despite cross-party support, concerns over civil liberties implications remain"

But the Protection of Children Bill has come under attack from a teachers' union, which argues that the measures are draconian and risk undermining the civil rights of those who work with children.

Ministers are backing the Bill, which would require employers to check a central register before recruiting anyone to work with young people.

People could be put on the register simply if they were suspected of abusing children.

But Labour MP Debra Shipley, who proposed the Private Members' Bill, said a stringent appeals procedure would protect those who were falsely accused of abuse.

Ms Shipley opened the debate on the Bill with a stern message to paedophiles: "We won't tolerate you or your cruel and destructive activities."

Debra Shipley: "Balancing civil rights and child protection"

She added: "This Bill seeks to protect the most vulnerable and innocent in our society. It closes down some of the avenues through which paedophiles operate."

Speaking for the Liberal Democrats, Jackie Ballard warned: "If this list is to have credibility, we have to ensure that those people who are included on it are there because they are a danger to children, and not someone who's fallen out with their employer and subject to malicious allegation."

The Bill, which received its second reading, stands a good chance of becoming law as it enjoys government support as well as substantial cross-party backing.

But the general secretary of the NASUWT union, Nigel de Gruchy, fears it could "sacrifice the basic principles of justice".

He said: "While I welcome the requirement to inform teachers and others if they are included on the 'outlaws' list', together with the right to appeal, I fear that the burden of proof for inclusion on the list is unacceptably lax.

Nigel de Gruchy: "The measures are unacceptable"

"I have been disturbed to hear supporters of the Bill saying 'it is a price worth paying' if a few innocents suffer to prevent some child abuse. Nobody has a right to demand that others must make such a sacrifice."

Earlier, Ms Shipley told BBC News Online that she hoped her Bill would stop paedophiles who have left a job because of suspicion of abuse in one region finding similar employment elsewhere.

The Stourbridge MP said referrals to the list would be made on "the balance of probabilities". If an employer "believes abuse is going on they need to refer it and have it investigated", she said.

"We don't want an either-or situation. What I want to do is to improve both the child's position and the civil liberties position," she said.

Debra Shipley outlines her Bill

Lists of sex offenders are kept by several government departments, but at present only guidelines exist covering their use, leaving employers no statutory duty to refer to them.

Ms Shipley's Bill would put in place a "one-stop shop" for employers to check on child abusers.

Those on the current lists are not necessarily informed of their inclusion and there is often no right of appeal.

The Bill has the backing of several children's charities including Childline, the Children's Society and the NSPCC.