Volunteers might be put off working with children, Mr Ball warned

The former host of the BBC show Think of a Number warned that volunteers such as those running football teams and music clubs would be "put off".

If the Safeguarding Vulnerable Groups Bill passes into law, employers will have to vet staff working with children or face a fine of up to �5,000.

The plan is supported by the main three parties and children's charity NSPCC.

'Like MI5'

Under the bill, employers would have to have staff checked for criminal offences using a new list.

This will combine the Criminal Records Bureau's list; List 99 - which contains the names of people banned from working in schools; and another list set up by the Protection of Children Act.

But Mr Ball told BBC Two's The Daily Politics: "This is penalising many, many wonderful people who want to help young people with activities like football and music.

"They won't be cleared until they get a similar level of clearance they get from MI5."

Mr Ball, father of ex-Radio One DJ and TV presenter Zoe Ball, added: "The checks will not stop criminal activity but they will put off volunteers.

"Many people of a gentle nature and spirit are very nervous about this."

He said of the bill: "It's so draconian. At every turn it's so drastic."

Newspaper columnist Kelvin McKenzie told the Daily Politics he sympathised with Mr Ball's position, but added that the bill would be worthwhile if it reduced "by just one" the number of victims of child abuse.

NSPCC chief executive Mary Marsh said: "Employers must do more than just tick the 'vetting box', as many abusers are not known to the criminal justice system.

"The government has laid crucial child protection foundations, now employers must play their part.

"This crucial new legislation will only work if organisations have robust child protection policies to back up the law."

The Bill follows the Bichard inquiry, which made recommendations after the murders of Jessica Chapman and Holly Wells, both 10, in Soham, Cambridgeshire, in 2002.