Controversial Queen's Speech legislation comes into effect on Wednesday extending child curfews from youngsters under-10 to teenagers up to 16-years-old.

The new measures are billed by the government as protecting both "communities as well as young people themselves".

The extended curfew orders cover the hours between 9.00pm and 6.00am and may last up to 90 days, after which they must be renewed.

Targeted geographically at so-called crime trouble spots, the Home Office claims that Glasgow's Hamilton Child Safety Initiative has proved the effectiveness of curfew schemes.

But the blanket bans aimed at tackling youth crime and "yob culture" have been attacked by human rights campaigners and opposition politicians.

Home Office minister, Beverley Hughes, has welcomed a new "tool that police and local authorities can use to tackle anti-social behaviour" and stressed that the extended bans, unused to date, will often be for the child's own good.

"By extending child curfew orders to include children up to the age of 15, police and local authorities are also better able to protect them from the risks of being unaccompanied on the streets at night; from adults such as drug dealers or pimps, or older peers encouraging them into criminal activities," she said.

Human rights campaigners are concerned that the new legislation will "cause unacceptable breaches of the human rights of those who are innocent".

Liberty director John Wadham said: "Curfew orders for children under 10 have never been used. Blanket bans in city centres restrict the movements of those with legitimate business. This is not a quick fix for crime."

"Rather than restricting civil liberties the government should be focusing resources on measures to prevent children from becoming involved in crime in the first place and by providing extra police to deal with crime that is committed," he said.

Chris Stanley, the youth crime spokesman for the National Association for the Care and Rehabilitation of Offenders, said that the new powers were in danger of "becoming the Dangerous Dogs Act of the juvenile justice system, popular with no one and virtually impossible to enforce".

"They will apply to any child living in the area, not just to those who are causing trouble. Enforcement could prove to be a nightmare, with tension and conflict between young people and the police increasing, not diminishing, as a result," he said.

"If these curfews are enforced, their impact will be felt most keenly by those children and young people who have never been in trouble with the police. For them, usual activities like going to the youth club, nipping down the road to the corner shop, and visiting friends, will become instantly unlawful unless they are accompanied at all times by an adult. There are surely better ways of tackling youth disorder and delinquency than this."

Stuart Waiton, a Glasgow community worker and author of "Scared of the kids: curfews, crime and the regulation of young people", argues that curfews "destroy communities" by exaggerating public fears and mistrust.

"The measures present all young people as a threat. Petty behaviour that all teenagers are associated with becomes criminalised," he warns.

Opposition politicians have joined the chorus of criticism. The Conservatives have attacked the new measures as a "gimmick and distraction" and attacked Labour for failing to deliver on crime.

Shadow Home Office minister, David Lidington, said: "Not one of these orders has been made. The orders are still too bureaucratic and unwieldy and Labour are yet to come to grips with the fact that there are insufficient police to enforce them."

"Today's re-announcement of this Labour gimmick is a distraction from the real issues surrounding juvenile crime. Conservatives would clear up the mess and confusion that Labour have created, and review the ways that these orders have been implemented," he said.

Lib Dem Home affairs spokesman, Simon Hughes, branded the new legislation as uncivilised and evidence of Labour's "authoritarian streak".

"Curfews have traditionally been reserved for wartime and national emergencies and in a civilised democracy that is how things should remain," he said. "The government should concentrate on positive measures to engage young people constructively in the community, not on giving more authoritarian powers to the police or the local authority."

Beverly Hughes said that the government's critics had "grossly underestimated'' the problem and the task facing the police.

"When people get up in the morning and they've had their car sprayed, their windows broken in, those are the issues that make life very difficult for people living on some of our neighbourhood estates. I think this scheme can help, not to impose in a draconian way restrictions on children, but to help the local community feel empowered to take responsibility for their own children in the longer term," she said.