David Blunkett has put child protection at the heart of new laws geared to the social and sexual attitudes of 21st century Britain.

The home secretary published a new Sex Offences Bill - a measure trailed in the Queen's Speech.

The government is to get tough on sex offenders but will repeal out-dated laws governing adult consensual sex.

"All crime has a damaging effect on individuals and communities but sex crimes particularly against children tears can tear apart the fabric of our society," Blunkett told MPs.

"The law on sex offences is archaic and incoherent, the Sex Offences Act is 46-years-old, and was mostly a simple consolidation of 19th century law."

"Our proposals for reform reflect changes in society and social attitudes and most importantly will better protect the public, particularly children and the vulnerable."

Other aspects of the overhaul have been trailed by Blunkett as a foundation for the "toughest child protection laws in the world".

Measures include a crackdown on internet paedophiles and see a new offence of internet "sexual grooming".

"The internet has opened up a new world, chat rooms allow children to contact each other, but we must deal with those who use the internet to groom children for abuse," he said.

Proposals go far beyond the web, with proposals to tackle abusers who use "contacts through the family" to lure their victims.

Giving sweets to a child or buying an ice cream for a young relative - activity normally seen as harmless under the law - could be regarded as criminal if there is evidence that an individual is "grooming" children for sexual abuse.

An offence that is set to carry a penalty of up to five years imprisonment.

The new offence has raised civil liberty concerns.

Human rights lawyer Shami Chakrabarti said: "The danger is that a law going further would mean prosecuting people not for anything they've done but for things someone thinks they might do - because someone is second-guessing their thoughts".

Liberty is worried that measures which inflame mistrust may put children at risk.

"If you make people afraid that talking to your neighbour's children could be seen as a paedophile offence, you actually make those children less safe. Neighbours and communities are important to keeping our children safe - both from abuse by strangers and, sadly, from the far greater risk of abuse in their own homes," said Chakrabarti.

Blunkett has also moved to close "loopholes" in current law on sex with under 16s.

"Consenting" sex between an adult and children between 13 and 16 with conviction carrying a maximum 14-year sentence.

"We do not believe that any very young child truly gives consent to an adult," the home secretary told the Commons.

Citing a case where a 32-year-old man had sex with a 12-year-old, Blunkett attacked a judge who said the offender "was not a paedophile".

"I beg to disagree," he said.

"In future such cases will be treated as rape. The issue of consent where a child of 12 or younger is involved will not be relevant."

Protection will also be given to the mentally ill or vulnerable.

Another new sex offence will target adults who have sex with prostitutes under 18-years of age.

Those convicted of a new crime of commercial sexual exploitation will face a severe penalty - up to life imprisonment for having sex with an under-age prostitute - even if they are 16 or 17, an age that would be legal otherwise.

A tightened sex offenders register will see 18,500 people currently convicted of sex offences forced to report to the police every year rather than every five years.

Those convicted of child sex "tourism" overseas will be compelled to register on their return to the UK or face five years in jail - a move that is set to herald greater international cooperation to crackdown on perverts.

Press reports also indicate that ministers are considering a controversial scheme to surgically implant electronic tracking tags in convicted paedophiles.

Blunkett announced measures to remove the defence in rape cases that "it was honestly believed that consent had been given".

"I want more criminals to be convicted," he said.

"Not at the expense of the innocent but because the cost to society giving more rights to victims and communities does not erode the rights of defendants. This is not a zero sum game.

"It is a miscarriage of justice when an innocent person is convicted but it is a travesty of justice when a guilty man walks free."

"Rape is one of the most terrible crimes there is."

Defendants will now be required to show that a mistake "was not only honest but in the circumstances a reasonable one".

"Mr Speaker, I think I ought to make it clear that I have no intention of asking anyone have to keep a pen and paper by the bedside."

But Blunkett stepped back from sex crime reform redefining consent in rape cases if the victim was drunk or high on drugs.

Concerns that such a move could enshrine a "drunk means no" policy in legislation and see a huge rise in the number of "date rape" cases coming before the courts were heard by the home secretary.

New laws will rule out a rape charge for those "inebriated" but an absence of consent will be assumed for those unconscious through drink or drugs.

"All rapes, including drug rape, will continue to carry a maximum penalty of life imprisonment," said Blunkett.

"A new offence of administering drugs with the intent to commit a sex crime will carry a maximum penalty of 10 years. We are sending out a clear message that such offences will be treated very seriously."

Reforms are not all tough new crackdowns on inappropriate behaviour.

"Our current laws on sex offences are not only archaic, they are discriminatory," said the home secretary.

"Criminalising acts between homosexuals that are not against the law for heterosexuals, goes against the principle of equality and previous reforms."

"We will therefore update the law to ensure equality of treatment. Consensual sex in private that does not harm anyone should no longer be a criminal offence."

Measures to reform Victorian sexual offence laws will be widely welcomed by MPs but could face opposition in the Lords.

Laws to be withdrawn include those which make it illegal for men to have sex in public places - a practice known as cottaging.

The move could reopen Conservative wounds on the issue of homosexuality.

Some senior Tories have criticised the plans, saying they will make public parks and lavatories "no-go" areas for young heterosexual men.

"For the sake of absolute clarity and my own peace of mind, I wish to point out that we will not be legalising sex in public. Existing provisions in the Public Order Act of 1986 together with common law offences will remain in place," said Blunkett.

"However, as well as these we will introduce a new offence to deal with specific sex acts in a public place. This will reinforce a sense of decency and respect for others. "

On balance the Conservatives welcomed reform - but pledged close scrutiny of the detailed legislation

Oliver Letwin praised a bill that "appears to have found a reasonable way through what is by any standards a nasty thicket".

The rape reforms, said the shadow home secretary, were unlikely to lead to increased convictions.

"But the home secretary has at least avoided doing any harm and for that we must be grateful," he said.

"Will the clauses defining the new test of reasonableness in relation to consent to a sexual act be drafted in such a way to reflect the delicate balance between the right of a woman to be protected from rape and the right of a man to be exonerated from slanderous allegations?"

Letwin echoed civil liberty concerns raised over new "grooming" offences.

"Will the clauses relating to grooming be drafted in such a way as adequately to distinguish between a manifestly evil pattern of genuine grooming and a harmless, or even arguably harmless, gesture by an adult to a child?," he said.

Lib Dems also welcomed the consultation and the presumption of "no consent" for under 13-year olds.

The party's home affairs spokesman Simon Hughes said: "We welcome the proposals."

"I hope the home secretary will see this as a measure that brings all sexual law reform together and if that's the case we will welcome a greater consolidating opportunity," he said.